维基百科上的解释：

　　RappinghiphopmusiccanbetracedbackinmanywaystoitsAfricanroots.CenturiesbeforetheUnitedStatesexisted,thegriotsofWestAfricaweredeliveringstoriesrhythmically,overdrumsandsparseinstrumentation.Becauseofthetimethathaspassedsincethegriotsofold,theconnectionsbetweenrapandtheAfricangriotsarewidelyestablished,butnotclear-cut.However,suchconnectionshavebeenacknowledgedbyrappers,modernday"griots",spokenwordartists,mainstreamnewssources,andacademics.

　　Bluesmusic,rootedintheworksongsandspiritualsofslaveryandinfluencedgreatlybyWestAfricanmusicaltraditions,wasfirstplayedbyblacks(andsomewhites)intheMississippiDeltaregionoftheUnitedStatesaroundthetimeoftheEmancipationProclamation.Grammy-winningbluesmusician/historianElijahWaldandothershavearguedthattheblueswerebeingrappedasearlyasthe1920s.Waldwentsofarastocallhiphop"thelivingblues."

　　TheMemphisJugBand,anearlybluesgroup,whoselyricalcontentandrhythmicsingingpredatedrapping.

　　TheMemphisJugBand,anearlybluesgroup,whoselyricalcontentandrhythmicsingingpredatedrapping.

　　Jazz,developedfromthebluesandotherAfrican-Americanmusicaltraditions,originatedaroundthebeginningofthe20thcentury.AccordingtoJohnSobol,thejazzmusicianandpoetwhowroteDigitopiaBlues,rap"bearsastrikingresemblancetotheevolutionofjazzbothstylisticallyandformally."

　　Duringthemid-20thcentury,themusicalcultureoftheCaribbeanwasconstantlyinfluencedbytheconcurrentchangesinAmericanmusic.Fromthe1950sthroughthe1970s,thedescendantsofCaribbeanslavesinJamaicaweremixingtheirtraditionalfolkmusicstylesofmentomusicwiththejazz,soul,rockandbluesofAmerica.InJamaica,thisinfluencedthecreationofreggaemusic(andlaterdancehall).Asearlyas1956,deejaysweretoasting(anAfricantraditionof"rappedout"talesofheroism)overdubbedJamaicanbeats.Itwascalled"rap",expandingtheword'searliermeaningintheAfrican-Americancommunity—"todiscussordebateinformally."

　　Etymology[Rap这个词本身的来历]：

　　Theuseofthewordtodescribequickspeechorreparteelongpredatesthemusicalform,meaningoriginally"tohit".ThewordhadbeenusedinBritishEnglishsincethe16thcentury,andspecificallymeaning"tosay"sincethe18th.ItwaspartoftheAfricanAmericandialectofEnglishinthe1960smeaning"toconverse",andverysoonafterthatinitspresentusageasatermdenotingthemusicalstyle.

　　Rappingcanbedeliveredoverabeatorwithoutaccompaniment.Stylistically,rapoccupiesagrayareaamongspeech,prose,poetry,andsong.Rapisderivedfromthegriots(folkpoets)ofWestAfrica,andJamaican-styletoasting.ItalsohasprecedentsintraditionalCelticmusic.Modernrapbattles,forinstance,bearastrikingresemblancetotheLimerickGame,atraditionalGaelicdrinkinggameinwhichpeoplecompetefornotorietybymakingupinsultinglimericksabouteachother,theloserhavingtobuythenextroundofdrinks.Likewise,puirtabeul,aformofScottishmouthmusicwasincorporatedintoAppalachianmusicandisanearlyancestorofmodernmouthpercussion,orbeatboxing.TheinfluenceofScottishandIrishmusiconhiphopisnotdirect,sincevirtuallyalloftheoriginatorsofhiphopculturewereAfricanAmerican,bu