-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CUayqaYbyl+NDH1uK2fA3CS97DW0jlDCpN0JrYVNtcZIC1x6Fa1eCyKBz+OlyW3D
 wP2Lu1tLhWQLTJO53XHYKA==

<SEC-DOCUMENT>0001319161-08-000011.txt : 20080818
<SEC-HEADER>0001319161-08-000011.hdr.sgml : 20080818
<ACCEPTANCE-DATETIME>20080818164021
ACCESSION NUMBER:		0001319161-08-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080815
FILED AS OF DATE:		20080818
DATE AS OF CHANGE:		20080818

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Warner Music Group Corp.
		CENTRAL INDEX KEY:			0001319161
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-AMUSEMENT & RECREATION SERVICES [7900]
		IRS NUMBER:				134271875
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		75 ROCKEFELLER PLAZA
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212-275-2000

	MAIL ADDRESS:	
		STREET 1:		75 ROCKEFELLER PLAZA
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WMG Parent Corp.
		DATE OF NAME CHANGE:	20050228

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ansorge Mark David
		CENTRAL INDEX KEY:			0001441731

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32502
		FILM NUMBER:		081025459

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		212.275.2000

	MAIL ADDRESS:	
		STREET 1:		75 ROCKEFELLER PLAZA
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001319161</issuerCik>
        <issuerName>Warner Music Group Corp.</issuerName>
        <issuerTradingSymbol>WMG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001441731</rptOwnerCik>
            <rptOwnerName>Ansorge Mark David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>75 ROCKEFELLER PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Human Resources</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.56</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-08-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>75000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-08-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.001</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>102000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the closing sales price on the grant date pursuant to the terms of the Warner Music Group Corp. 2005 Omnibus Award Plan.</footnote>
        <footnote id="F2">The option generally vests and becomes exercisable in four equal installments on the day prior to each of the first through the fourth anniversaries of the grant date, which was 8/15/08, subject to the employee's continued employment.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Trent N. Tappe as attorney-in-fact</signatureName>
        <signatureDate>2008-08-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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