<?xml version="1.0" encoding="utf-8"?>
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <!-- INTEGIX by Ez-XBRL -->
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" roleURI="http://www.xbrl.org/2009/role/negatedLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodEndLabel" roleURI="http://www.xbrl.org/2009/role/negatedPeriodEndLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel" roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel" roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedNetLabel" roleURI="http://www.xbrl.org/2009/role/negatedNetLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel" roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel"/>
  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" roleURI="http://www.xbrl.org/2009/role/netLabel"/>
  <labelLink xlink:type="extended" xlink:role="http://www.xbrl.org/2003/role/link">
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_BankLoanRiskMember" xlink:label="loc_ck0001379400_BankLoanRiskMember_1"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_BankLoanRiskMember" xlink:label="loc_ck0001379400_BankLoanRiskMember_2"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember" xlink:label="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_3"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember" xlink:label="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_4"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember" xlink:label="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_5"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CashHoldingsRiskMember" xlink:label="loc_ck0001379400_CashHoldingsRiskMember_6"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommittedFacilityAgreementMember" xlink:label="loc_ck0001379400_CommittedFacilityAgreementMember_7"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommittedFacilityAgreementMember" xlink:label="loc_ck0001379400_CommittedFacilityAgreementMember_8"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommonShareMember" xlink:label="loc_ck0001379400_CommonShareMember_9"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommonShareMember" xlink:label="loc_ck0001379400_CommonShareMember_10"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommonShareMember" xlink:label="loc_ck0001379400_CommonShareMember_11"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommonSharesMember" xlink:label="loc_ck0001379400_CommonSharesMember_12"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CommonSharesMember" xlink:label="loc_ck0001379400_CommonSharesMember_13"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ContingentLiabilitiesRiskMember" xlink:label="loc_ck0001379400_ContingentLiabilitiesRiskMember_14"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ConvertibleHedgingAndShortSalesRiskMember" xlink:label="loc_ck0001379400_ConvertibleHedgingAndShortSalesRiskMember_15"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ConvertibleSecuritiesRiskMember" xlink:label="loc_ck0001379400_ConvertibleSecuritiesRiskMember_16"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CorrelationRiskMember" xlink:label="loc_ck0001379400_CorrelationRiskMember_17"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CounterPartyAndSettlementRiskMember" xlink:label="loc_ck0001379400_CounterPartyAndSettlementRiskMember_18"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CounterPartyAndSettlementRiskMember" xlink:label="loc_ck0001379400_CounterPartyAndSettlementRiskMember_19"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CovenantLiteLoansRiskMember" xlink:label="loc_ck0001379400_CovenantLiteLoansRiskMember_20"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CreditAndMarketRiskMember" xlink:label="loc_ck0001379400_CreditAndMarketRiskMember_21"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CreditAndMarketRiskMember" xlink:label="loc_ck0001379400_CreditAndMarketRiskMember_22"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CreditFacilityMember" xlink:label="loc_ck0001379400_CreditFacilityMember_23"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CreditFacilityMember" xlink:label="loc_ck0001379400_CreditFacilityMember_24"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CurrencyRiskMember" xlink:label="loc_ck0001379400_CurrencyRiskMember_25"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CurrencyRiskMember" xlink:label="loc_ck0001379400_CurrencyRiskMember_26"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_CybersecurityRiskMember" xlink:label="loc_ck0001379400_CybersecurityRiskMember_27"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DebtSecuritiesRiskMember" xlink:label="loc_ck0001379400_DebtSecuritiesRiskMember_28"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DeclineInNetAssetValueRiskMember" xlink:label="loc_ck0001379400_DeclineInNetAssetValueRiskMember_29"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DefaultRiskMember" xlink:label="loc_ck0001379400_DefaultRiskMember_30"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DerivativesRiskMember" xlink:label="loc_ck0001379400_DerivativesRiskMember_31"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DiminishedVotingPowerAndExcessCashRiskMember" xlink:label="loc_ck0001379400_DiminishedVotingPowerAndExcessCashRiskMember_32"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DurationMismatchRiskMember" xlink:label="loc_ck0001379400_DurationMismatchRiskMember_33"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_DurationRiskMember" xlink:label="loc_ck0001379400_DurationRiskMember_34"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EarlyRedemptionRiskMember" xlink:label="loc_ck0001379400_EarlyRedemptionRiskMember_35"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EmergingMarketsRiskMember" xlink:label="loc_ck0001379400_EmergingMarketsRiskMember_36"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EmergingMarketsRiskMember" xlink:label="loc_ck0001379400_EmergingMarketsRiskMember_37"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember" xlink:label="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_38"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember" xlink:label="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_39"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember" xlink:label="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_40"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_EquitySecuritiesRiskMember" xlink:label="loc_ck0001379400_EquitySecuritiesRiskMember_41"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_FacilityMember" xlink:label="loc_ck0001379400_FacilityMember_42"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember" xlink:label="loc_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_43"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember" xlink:label="loc_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_44"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_FeeForOptionalSharesPurchasesMember" xlink:label="loc_ck0001379400_FeeForOptionalSharesPurchasesMember_45"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_FeeForOptionalSharesPurchasesMember" xlink:label="loc_ck0001379400_FeeForOptionalSharesPurchasesMember_46"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ForeignSecuritiesRiskMember" xlink:label="loc_ck0001379400_ForeignSecuritiesRiskMember_47"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ForwardCurrencyExchangeContractsRiskMember" xlink:label="loc_ck0001379400_ForwardCurrencyExchangeContractsRiskMember_48"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_GeneralDerivativeRiskMember" xlink:label="loc_ck0001379400_GeneralDerivativeRiskMember_49"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_GeneralRiskMember" xlink:label="loc_ck0001379400_GeneralRiskMember_50"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_GeneralRiskMember" xlink:label="loc_ck0001379400_GeneralRiskMember_51"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_GeographicConcentrationRisksMember" xlink:label="loc_ck0001379400_GeographicConcentrationRisksMember_52"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember" xlink:label="loc_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_53"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember" xlink:label="loc_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_54"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_HighYieldSecuritiesRiskMember" xlink:label="loc_ck0001379400_HighYieldSecuritiesRiskMember_55"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InflationRiskMember" xlink:label="loc_ck0001379400_InflationRiskMember_56"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InflationRisksMember" xlink:label="loc_ck0001379400_InflationRisksMember_57"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InflationRisksMember" xlink:label="loc_ck0001379400_InflationRisksMember_58"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InflationRisksMember" xlink:label="loc_ck0001379400_InflationRisksMember_59"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestRateRisks1Member" xlink:label="loc_ck0001379400_InterestRateRisks1Member_60"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestRateRisks1Member" xlink:label="loc_ck0001379400_InterestRateRisks1Member_61"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestRateRisksMember" xlink:label="loc_ck0001379400_InterestRateRisksMember_62"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestRateTransactionsRiskMember" xlink:label="loc_ck0001379400_InterestRateTransactionsRiskMember_63"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestsRateRiskMember" xlink:label="loc_ck0001379400_InterestsRateRiskMember_64"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestsRateRiskMember" xlink:label="loc_ck0001379400_InterestsRateRiskMember_65"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InterestsRateRiskMember" xlink:label="loc_ck0001379400_InterestsRateRiskMember_66"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember" xlink:label="loc_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_67"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember" xlink:label="loc_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_68"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_LeverageRiskMember" xlink:label="loc_ck0001379400_LeverageRiskMember_69"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_LiquidityRiskMember" xlink:label="loc_ck0001379400_LiquidityRiskMember_70"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_LoanMember" xlink:label="loc_ck0001379400_LoanMember_71"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_LoanRiskMember" xlink:label="loc_ck0001379400_LoanRiskMember_72"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ManagementRiskMember" xlink:label="loc_ck0001379400_ManagementRiskMember_73"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesMember_74"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_75"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_76"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_77"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_78"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_79"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_80"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_81"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_82"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_83"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_84"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_85"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember" xlink:label="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_86"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MarketDiscountRisk1Member" xlink:label="loc_ck0001379400_MarketDiscountRisk1Member_87"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MarketDiscountRisk1Member" xlink:label="loc_ck0001379400_MarketDiscountRisk1Member_88"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MarketDiscountRiskMember" xlink:label="loc_ck0001379400_MarketDiscountRiskMember_89"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MarketDisruptionRiskMember" xlink:label="loc_ck0001379400_MarketDisruptionRiskMember_90"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MarketImpactRiskMember" xlink:label="loc_ck0001379400_MarketImpactRiskMember_91"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MasterLimitedPartnershipsRiskMember" xlink:label="loc_ck0001379400_MasterLimitedPartnershipsRiskMember_92"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_MaturityRiskMember" xlink:label="loc_ck0001379400_MaturityRiskMember_93"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NonConvertibleIncomeSecuritiesRiskMember" xlink:label="loc_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_94"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NonConvertibleIncomeSecuritiesRiskMember" xlink:label="loc_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_95"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NonUnitedStatesGovernmentObligationRiskMember" xlink:label="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_96"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NonUnitedStatesGovernmentObligationRiskMember" xlink:label="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_97"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NonUnitedStatesGovernmentObligationRiskMember" xlink:label="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_98"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_Notes2035Member" xlink:label="loc_ck0001379400_Notes2035Member_99"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NotesMember" xlink:label="loc_ck0001379400_NotesMember_100"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_NotesMember" xlink:label="loc_ck0001379400_NotesMember_101"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember" xlink:label="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_102"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember" xlink:label="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_103"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember" xlink:label="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_104"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_PortfolioSelectionRiskMember" xlink:label="loc_ck0001379400_PortfolioSelectionRiskMember_105"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_PortfolioTurnoverRiskMember" xlink:label="loc_ck0001379400_PortfolioTurnoverRiskMember_106"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_PreferredSharesMember" xlink:label="loc_ck0001379400_PreferredSharesMember_107"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_PreferredSharesMember" xlink:label="loc_ck0001379400_PreferredSharesMember_108"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RatingsAndAssetCoverageRiskMember" xlink:label="loc_ck0001379400_RatingsAndAssetCoverageRiskMember_109"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RecentMarketEventsRiskMember" xlink:label="loc_ck0001379400_RecentMarketEventsRiskMember_110"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_ReductionOfLeverageRiskMember" xlink:label="loc_ck0001379400_ReductionOfLeverageRiskMember_111"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RegulatoryRiskMember" xlink:label="loc_ck0001379400_RegulatoryRiskMember_112"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember" xlink:label="loc_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_113"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember" xlink:label="loc_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_114"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RisksAssociatedWithOptionsMember" xlink:label="loc_ck0001379400_RisksAssociatedWithOptionsMember_115"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_RisksAssociatedWithOptionsMember" xlink:label="loc_ck0001379400_RisksAssociatedWithOptionsMember_116"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_Rule144SecuritiesRiskMember" xlink:label="loc_ck0001379400_Rule144SecuritiesRiskMember_117"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_Rule144SecuritiesRiskMember" xlink:label="loc_ck0001379400_Rule144SecuritiesRiskMember_118"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember" xlink:label="loc_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_119"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember" xlink:label="loc_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_120"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SecondaryMarketRiskMember" xlink:label="loc_ck0001379400_SecondaryMarketRiskMember_121"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SectorRiskMember" xlink:label="loc_ck0001379400_SectorRiskMember_122"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SecuredOvernightFinancingRateRiskMember" xlink:label="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_123"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SecuredOvernightFinancingRateRiskMember" xlink:label="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_124"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SecuredOvernightFinancingRateRiskMember" xlink:label="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_125"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SeniorLeverageRiskMember" xlink:label="loc_ck0001379400_SeniorLeverageRiskMember_126"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SeriesATermPreferredStockDue2025Member" xlink:label="loc_ck0001379400_SeriesATermPreferredStockDue2025Member_127"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_SyntheticConvertibleInstrumentsRiskMember" xlink:label="loc_ck0001379400_SyntheticConvertibleInstrumentsRiskMember_128"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_TaxRiskMember" xlink:label="loc_ck0001379400_TaxRiskMember_129"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember" xlink:label="loc_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_130"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember" xlink:label="loc_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_131"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_UnitedStatesGovernmentSecurityRiskMember" xlink:label="loc_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_132"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_UnitedStatesGovernmentSecurityRiskMember" xlink:label="loc_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_133"/>
    <loc xlink:type="locator" xlink:href="ck0001379400-20260807.xsd#ck0001379400_VolatilityRiskMember" xlink:label="loc_ck0001379400_VolatilityRiskMember_134"/>
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_135"/>
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_136"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_BankLoanRiskMember_0" xml:lang="en-US">Bank Loan Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_BankLoanRiskMember_1" xml:lang="en-US">Represent information about the bank loan risk member.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_0" xml:lang="en-US">Benchmark Rate Risk And London Interbank Offered Rate Cessation [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_1" xml:lang="en-US">Benchmark Rate Risk And London Interbank Offered Rate Cessation [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_2" xml:lang="en-US">Benchmark Rate Risk and LIBOR Cessation [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CashHoldingsRiskMember_0" xml:lang="en-US">Cash Holdings Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CommittedFacilityAgreementMember_0" xml:lang="en-US">Information about committed facility agreement.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CommittedFacilityAgreementMember_1" xml:lang="en-US">Committed Facility Agreement [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CommonShareMember_0" xml:lang="en-US">Common Share [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CommonShareMember_1" xml:lang="en-US">Common Share [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_ck0001379400_CommonShareMember_2" xml:lang="en-US">Common Share [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CommonSharesMember_0" xml:lang="en-US">Common Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CommonSharesMember_1" xml:lang="en-US">Common Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ContingentLiabilitiesRiskMember_0" xml:lang="en-US">Contingent Liabilities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ConvertibleHedgingAndShortSalesRiskMember_0" xml:lang="en-US">Convertible Hedging And Short Sales Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ConvertibleSecuritiesRiskMember_0" xml:lang="en-US">Convertible Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CorrelationRiskMember_0" xml:lang="en-US">Correlation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CounterPartyAndSettlementRiskMember_0" xml:lang="en-US">Counter Party And Settlement Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CounterPartyAndSettlementRiskMember_1" xml:lang="en-US">Counter Party And Settlement Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CovenantLiteLoansRiskMember_0" xml:lang="en-US">Covenant Lite Loans Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CreditAndMarketRiskMember_0" xml:lang="en-US">Credit And Market Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CreditAndMarketRiskMember_1" xml:lang="en-US">Credit and Market Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CreditFacilityMember_0" xml:lang="en-US">Credit Facility [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CreditFacilityMember_1" xml:lang="en-US">Information about credit facility.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CurrencyRiskMember_0" xml:lang="en-US">Currency Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_CurrencyRiskMember_1" xml:lang="en-US">Currency Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_CybersecurityRiskMember_0" xml:lang="en-US">Cybersecurity Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DebtSecuritiesRiskMember_0" xml:lang="en-US">Debt Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DeclineInNetAssetValueRiskMember_0" xml:lang="en-US">Decline In Net Asset Value Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DefaultRiskMember_0" xml:lang="en-US">Default Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DerivativesRiskMember_0" xml:lang="en-US">Derivatives Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DiminishedVotingPowerAndExcessCashRiskMember_0" xml:lang="en-US">Diminished Voting Power And Excess Cash Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DurationMismatchRiskMember_0" xml:lang="en-US">Duration Mismatch Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_DurationRiskMember_0" xml:lang="en-US">Duration Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_EarlyRedemptionRiskMember_0" xml:lang="en-US">Early Redemption Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_EmergingMarketsRiskMember_0" xml:lang="en-US">Emerging Markets Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_EmergingMarketsRiskMember_1" xml:lang="en-US">Emerging Markets Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_0" xml:lang="en-US">Environmental Social Governance Integration Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_1" xml:lang="en-US">Environmental, Social, and Governance Integration Risk.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_2" xml:lang="en-US">ESG Integration Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_EquitySecuritiesRiskMember_0" xml:lang="en-US">Equity Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_FacilityMember_0" xml:lang="en-US">Facility [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_0" xml:lang="en-US">Fee For Open Market Purchases Of Common Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_1" xml:lang="en-US">Fee For Open Market Purchases Of Common Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_FeeForOptionalSharesPurchasesMember_0" xml:lang="en-US">Fee For Optional Shares Purchases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_FeeForOptionalSharesPurchasesMember_1" xml:lang="en-US">Fee For Optional Shares Purchases [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ForeignSecuritiesRiskMember_0" xml:lang="en-US">Foreign Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ForwardCurrencyExchangeContractsRiskMember_0" xml:lang="en-US">Forward Currency Exchange Contracts Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_GeneralDerivativeRiskMember_0" xml:lang="en-US">General Derivative Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_GeneralRiskMember_0" xml:lang="en-US">General Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_GeneralRiskMember_1" xml:lang="en-US">General Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_GeographicConcentrationRisksMember_0" xml:lang="en-US">Geographic Concentration Risks [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_0" xml:lang="en-US">High Yield Bonds And Other Lower Rated Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_1" xml:lang="en-US">High-yield Bonds And Other Lower-rated Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_HighYieldSecuritiesRiskMember_0" xml:lang="en-US">High Yield Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InflationRiskMember_0" xml:lang="en-US">Inflation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InflationRisksMember_0" xml:lang="en-US">Inflation Risks [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_InflationRisksMember_1" xml:lang="en-US">Inflation Risks [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_InflationRisksMember_2" xml:lang="en-US">Inflation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InterestRateRisks1Member_0" xml:lang="en-US">Interest Rate Risks 1 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_ck0001379400_InterestRateRisks1Member_1" xml:lang="en-US">Interest Rate Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InterestRateRisksMember_0" xml:lang="en-US">Interest Rate Risks [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InterestRateTransactionsRiskMember_0" xml:lang="en-US">Interest Rate Transactions Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_InterestsRateRiskMember_0" xml:lang="en-US">Represent information about the interest rate risk member.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InterestsRateRiskMember_1" xml:lang="en-US">Interests Rate Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_InterestsRateRiskMember_2" xml:lang="en-US">Interest Rate Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_0" xml:lang="en-US">Investing In Real Estate Investment Trusts Risk Reit [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_1" xml:lang="en-US">REIT Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_LeverageRiskMember_0" xml:lang="en-US">Leverage Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_LiquidityRiskMember_0" xml:lang="en-US">Liquidity Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_LoanMember_0" xml:lang="en-US">Loan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_LoanRiskMember_0" xml:lang="en-US">Loan Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ManagementRiskMember_0" xml:lang="en-US">Management Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesMember_0" xml:lang="en-US">Mandatory Redeemable Preferred Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_0" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_1" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_2" xml:lang="en-US">MRPS-Series C [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_0" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series D [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_1" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series D [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_2" xml:lang="en-US">MRPS-Series D [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_0" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series E [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_1" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series E [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_2" xml:lang="en-US">MRPS-Series E [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_0" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series G [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_1" xml:lang="en-US">Mandatory Redeemable Preferred Shares Series G [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_2" xml:lang="en-US">MRPS-Series G [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_MarketDiscountRisk1Member_0" xml:lang="en-US">Market Discount Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MarketDiscountRisk1Member_1" xml:lang="en-US">Market Discount Risk 1 Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MarketDiscountRiskMember_0" xml:lang="en-US">Market Discount Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MarketDisruptionRiskMember_0" xml:lang="en-US">Market Disruption Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MarketImpactRiskMember_0" xml:lang="en-US">Market Impact Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MasterLimitedPartnershipsRiskMember_0" xml:lang="en-US">Master Limited Partnerships Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_MaturityRiskMember_0" xml:lang="en-US">Maturity Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_0" xml:lang="en-US">Non Convertible Income Securities Risk Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_1" xml:lang="en-US">Non-Convertible Income Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_0" xml:lang="en-US">Non-US Government Obligation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_1" xml:lang="en-US">Non United States Government Obligation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_2" xml:lang="en-US">Non United States Government Obligation Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_Notes2035Member_0" xml:lang="en-US">Notes 2035 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_NotesMember_0" xml:lang="en-US">Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_NotesMember_1" xml:lang="en-US">Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_0" xml:lang="en-US">Other Investment Companies (including ETFs) Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_1" xml:lang="en-US">Other Investment Companies Including Exchange Traded Fund Risk Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_2" xml:lang="en-US">Other Investment Companies Including Exchange Traded Fund Risk Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_PortfolioSelectionRiskMember_0" xml:lang="en-US">Portfolio Selection Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_PortfolioTurnoverRiskMember_0" xml:lang="en-US">Portfolio Turnover Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_PreferredSharesMember_0" xml:lang="en-US">Preferred Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_PreferredSharesMember_1" xml:lang="en-US">Preferred Shares [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_RatingsAndAssetCoverageRiskMember_0" xml:lang="en-US">Ratings And Asset Coverage Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_RecentMarketEventsRiskMember_0" xml:lang="en-US">Recent Market Events Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_ReductionOfLeverageRiskMember_0" xml:lang="en-US">Reduction Of Leverage Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_RegulatoryRiskMember_0" xml:lang="en-US">Regulatory Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_0" xml:lang="en-US">Risks Associated with Foreign Securities And Currencies [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_1" xml:lang="en-US">Risks Associated With Foreign Securities And Currencies [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_RisksAssociatedWithOptionsMember_0" xml:lang="en-US">Risks Associated With Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_RisksAssociatedWithOptionsMember_1" xml:lang="en-US">Risks Associated with Options [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_Rule144SecuritiesRiskMember_0" xml:lang="en-US">Rule 144A Securities Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_Rule144SecuritiesRiskMember_1" xml:lang="en-US">Rule 144 Securities Risk Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_0" xml:lang="en-US">Sales Of Shares Held In Dividend Reinvestment Account [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_1" xml:lang="en-US">Sales Of Shares Held In Dividend Reinvestment Account [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SecondaryMarketRiskMember_0" xml:lang="en-US">Secondary Market Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SectorRiskMember_0" xml:lang="en-US">Sector Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_0" xml:lang="en-US">Secured Overnight Financing Rate Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_1" xml:lang="en-US">Secured Overnight Financing Rate Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_2" xml:lang="en-US">SOFR Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SeniorLeverageRiskMember_0" xml:lang="en-US">Senior Leverage Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SeriesATermPreferredStockDue2025Member_0" xml:lang="en-US">Series A Term Preferred Stock Due 2025 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_SyntheticConvertibleInstrumentsRiskMember_0" xml:lang="en-US">Synthetic Convertible Instruments Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_TaxRiskMember_0" xml:lang="en-US">Tax Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_0" xml:lang="en-US">Transaction Fee Of One One Nine Percent Of Offering Price [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_1" xml:lang="en-US">Transaction Fee Of One One Nine Percent Of Offering Price [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_0" xml:lang="en-US">United States Government Security Risk Member</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_1" xml:lang="en-US">U.S. Government Security Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_ck0001379400_VolatilityRiskMember_0" xml:lang="en-US">Volatility Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfStockDomain_0" xml:lang="en-US">Class of Stock [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DebtInstrumentNameDomain_0" xml:lang="en-US">Debt Instrument Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_BankLoanRiskMember_1" xlink:to="lab_ck0001379400_BankLoanRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_BankLoanRiskMember_2" xlink:to="lab_ck0001379400_BankLoanRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_3" xlink:to="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_4" xlink:to="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_5" xlink:to="lab_ck0001379400_BenchmarkRateRiskAndLondonInterbankOfferedRateCessationMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CashHoldingsRiskMember_6" xlink:to="lab_ck0001379400_CashHoldingsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommittedFacilityAgreementMember_7" xlink:to="lab_ck0001379400_CommittedFacilityAgreementMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommittedFacilityAgreementMember_8" xlink:to="lab_ck0001379400_CommittedFacilityAgreementMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommonShareMember_9" xlink:to="lab_ck0001379400_CommonShareMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommonShareMember_10" xlink:to="lab_ck0001379400_CommonShareMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommonShareMember_11" xlink:to="lab_ck0001379400_CommonShareMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommonSharesMember_12" xlink:to="lab_ck0001379400_CommonSharesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CommonSharesMember_13" xlink:to="lab_ck0001379400_CommonSharesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ContingentLiabilitiesRiskMember_14" xlink:to="lab_ck0001379400_ContingentLiabilitiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ConvertibleHedgingAndShortSalesRiskMember_15" xlink:to="lab_ck0001379400_ConvertibleHedgingAndShortSalesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ConvertibleSecuritiesRiskMember_16" xlink:to="lab_ck0001379400_ConvertibleSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CorrelationRiskMember_17" xlink:to="lab_ck0001379400_CorrelationRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CounterPartyAndSettlementRiskMember_18" xlink:to="lab_ck0001379400_CounterPartyAndSettlementRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CounterPartyAndSettlementRiskMember_19" xlink:to="lab_ck0001379400_CounterPartyAndSettlementRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CovenantLiteLoansRiskMember_20" xlink:to="lab_ck0001379400_CovenantLiteLoansRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CreditAndMarketRiskMember_21" xlink:to="lab_ck0001379400_CreditAndMarketRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CreditAndMarketRiskMember_22" xlink:to="lab_ck0001379400_CreditAndMarketRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CreditFacilityMember_23" xlink:to="lab_ck0001379400_CreditFacilityMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CreditFacilityMember_24" xlink:to="lab_ck0001379400_CreditFacilityMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CurrencyRiskMember_25" xlink:to="lab_ck0001379400_CurrencyRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CurrencyRiskMember_26" xlink:to="lab_ck0001379400_CurrencyRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_CybersecurityRiskMember_27" xlink:to="lab_ck0001379400_CybersecurityRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DebtSecuritiesRiskMember_28" xlink:to="lab_ck0001379400_DebtSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DeclineInNetAssetValueRiskMember_29" xlink:to="lab_ck0001379400_DeclineInNetAssetValueRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DefaultRiskMember_30" xlink:to="lab_ck0001379400_DefaultRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DerivativesRiskMember_31" xlink:to="lab_ck0001379400_DerivativesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DiminishedVotingPowerAndExcessCashRiskMember_32" xlink:to="lab_ck0001379400_DiminishedVotingPowerAndExcessCashRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DurationMismatchRiskMember_33" xlink:to="lab_ck0001379400_DurationMismatchRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_DurationRiskMember_34" xlink:to="lab_ck0001379400_DurationRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EarlyRedemptionRiskMember_35" xlink:to="lab_ck0001379400_EarlyRedemptionRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EmergingMarketsRiskMember_36" xlink:to="lab_ck0001379400_EmergingMarketsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EmergingMarketsRiskMember_37" xlink:to="lab_ck0001379400_EmergingMarketsRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_38" xlink:to="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_39" xlink:to="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_40" xlink:to="lab_ck0001379400_EnvironmentalSocialGovernanceIntegrationRiskMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_EquitySecuritiesRiskMember_41" xlink:to="lab_ck0001379400_EquitySecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_FacilityMember_42" xlink:to="lab_ck0001379400_FacilityMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_43" xlink:to="lab_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_44" xlink:to="lab_ck0001379400_FeeForOpenMarketPurchasesOfCommonSharesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_FeeForOptionalSharesPurchasesMember_45" xlink:to="lab_ck0001379400_FeeForOptionalSharesPurchasesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_FeeForOptionalSharesPurchasesMember_46" xlink:to="lab_ck0001379400_FeeForOptionalSharesPurchasesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ForeignSecuritiesRiskMember_47" xlink:to="lab_ck0001379400_ForeignSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ForwardCurrencyExchangeContractsRiskMember_48" xlink:to="lab_ck0001379400_ForwardCurrencyExchangeContractsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_GeneralDerivativeRiskMember_49" xlink:to="lab_ck0001379400_GeneralDerivativeRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_GeneralRiskMember_50" xlink:to="lab_ck0001379400_GeneralRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_GeneralRiskMember_51" xlink:to="lab_ck0001379400_GeneralRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_GeographicConcentrationRisksMember_52" xlink:to="lab_ck0001379400_GeographicConcentrationRisksMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_53" xlink:to="lab_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_54" xlink:to="lab_ck0001379400_HighYieldBondsAndOtherLowerRatedSecuritiesRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_HighYieldSecuritiesRiskMember_55" xlink:to="lab_ck0001379400_HighYieldSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InflationRiskMember_56" xlink:to="lab_ck0001379400_InflationRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InflationRisksMember_57" xlink:to="lab_ck0001379400_InflationRisksMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InflationRisksMember_58" xlink:to="lab_ck0001379400_InflationRisksMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InflationRisksMember_59" xlink:to="lab_ck0001379400_InflationRisksMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestRateRisks1Member_60" xlink:to="lab_ck0001379400_InterestRateRisks1Member_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestRateRisks1Member_61" xlink:to="lab_ck0001379400_InterestRateRisks1Member_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestRateRisksMember_62" xlink:to="lab_ck0001379400_InterestRateRisksMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestRateTransactionsRiskMember_63" xlink:to="lab_ck0001379400_InterestRateTransactionsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestsRateRiskMember_64" xlink:to="lab_ck0001379400_InterestsRateRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestsRateRiskMember_65" xlink:to="lab_ck0001379400_InterestsRateRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InterestsRateRiskMember_66" xlink:to="lab_ck0001379400_InterestsRateRiskMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_67" xlink:to="lab_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_68" xlink:to="lab_ck0001379400_InvestingInRealEstateInvestmentTrustsRiskReitMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_LeverageRiskMember_69" xlink:to="lab_ck0001379400_LeverageRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_LiquidityRiskMember_70" xlink:to="lab_ck0001379400_LiquidityRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_LoanMember_71" xlink:to="lab_ck0001379400_LoanMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_LoanRiskMember_72" xlink:to="lab_ck0001379400_LoanRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ManagementRiskMember_73" xlink:to="lab_ck0001379400_ManagementRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesMember_74" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_75" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_76" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_77" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesCMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_78" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_79" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_80" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesDMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_81" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_82" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_83" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesEMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_84" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_85" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_86" xlink:to="lab_ck0001379400_MandatoryRedeemablePreferredSharesSeriesGMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MarketDiscountRisk1Member_87" xlink:to="lab_ck0001379400_MarketDiscountRisk1Member_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MarketDiscountRisk1Member_88" xlink:to="lab_ck0001379400_MarketDiscountRisk1Member_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MarketDiscountRiskMember_89" xlink:to="lab_ck0001379400_MarketDiscountRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MarketDisruptionRiskMember_90" xlink:to="lab_ck0001379400_MarketDisruptionRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MarketImpactRiskMember_91" xlink:to="lab_ck0001379400_MarketImpactRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MasterLimitedPartnershipsRiskMember_92" xlink:to="lab_ck0001379400_MasterLimitedPartnershipsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_MaturityRiskMember_93" xlink:to="lab_ck0001379400_MaturityRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_94" xlink:to="lab_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_95" xlink:to="lab_ck0001379400_NonConvertibleIncomeSecuritiesRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_96" xlink:to="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_97" xlink:to="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_98" xlink:to="lab_ck0001379400_NonUnitedStatesGovernmentObligationRiskMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_Notes2035Member_99" xlink:to="lab_ck0001379400_Notes2035Member_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NotesMember_100" xlink:to="lab_ck0001379400_NotesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_NotesMember_101" xlink:to="lab_ck0001379400_NotesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_102" xlink:to="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_103" xlink:to="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_104" xlink:to="lab_ck0001379400_OtherInvestmentCompaniesIncludingExchangeTradedFundRiskMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_PortfolioSelectionRiskMember_105" xlink:to="lab_ck0001379400_PortfolioSelectionRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_PortfolioTurnoverRiskMember_106" xlink:to="lab_ck0001379400_PortfolioTurnoverRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_PreferredSharesMember_107" xlink:to="lab_ck0001379400_PreferredSharesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_PreferredSharesMember_108" xlink:to="lab_ck0001379400_PreferredSharesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RatingsAndAssetCoverageRiskMember_109" xlink:to="lab_ck0001379400_RatingsAndAssetCoverageRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RecentMarketEventsRiskMember_110" xlink:to="lab_ck0001379400_RecentMarketEventsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_ReductionOfLeverageRiskMember_111" xlink:to="lab_ck0001379400_ReductionOfLeverageRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RegulatoryRiskMember_112" xlink:to="lab_ck0001379400_RegulatoryRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_113" xlink:to="lab_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_114" xlink:to="lab_ck0001379400_RisksAssociatedWithForeignSecuritiesAndCurrenciesMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RisksAssociatedWithOptionsMember_115" xlink:to="lab_ck0001379400_RisksAssociatedWithOptionsMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_RisksAssociatedWithOptionsMember_116" xlink:to="lab_ck0001379400_RisksAssociatedWithOptionsMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_Rule144SecuritiesRiskMember_117" xlink:to="lab_ck0001379400_Rule144SecuritiesRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_Rule144SecuritiesRiskMember_118" xlink:to="lab_ck0001379400_Rule144SecuritiesRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_119" xlink:to="lab_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_120" xlink:to="lab_ck0001379400_SalesOfSharesHeldInDividendReinvestmentAccountMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SecondaryMarketRiskMember_121" xlink:to="lab_ck0001379400_SecondaryMarketRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SectorRiskMember_122" xlink:to="lab_ck0001379400_SectorRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_123" xlink:to="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_124" xlink:to="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SecuredOvernightFinancingRateRiskMember_125" xlink:to="lab_ck0001379400_SecuredOvernightFinancingRateRiskMember_2"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SeniorLeverageRiskMember_126" xlink:to="lab_ck0001379400_SeniorLeverageRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SeriesATermPreferredStockDue2025Member_127" xlink:to="lab_ck0001379400_SeriesATermPreferredStockDue2025Member_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_SyntheticConvertibleInstrumentsRiskMember_128" xlink:to="lab_ck0001379400_SyntheticConvertibleInstrumentsRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_TaxRiskMember_129" xlink:to="lab_ck0001379400_TaxRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_130" xlink:to="lab_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_131" xlink:to="lab_ck0001379400_TransactionFeeOfOneOneNinePercentOfOfferingPriceMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_132" xlink:to="lab_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_133" xlink:to="lab_ck0001379400_UnitedStatesGovernmentSecurityRiskMember_1"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001379400_VolatilityRiskMember_134" xlink:to="lab_ck0001379400_VolatilityRiskMember_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfStockDomain_135" xlink:to="lab_us-gaap_ClassOfStockDomain_0"/>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_136" xlink:to="lab_us-gaap_DebtInstrumentNameDomain_0"/>
  </labelLink>
</linkbase>
