Truth..it started off with Kool Herc and other Jamacian DJ's mixing music and spinning records.....
Then they would make their hype shoutouts sound "cool" by making them rhyme....once a culture evolved (hip hop is about freedom of ones self and the expression of that,etc.) They began to write for it w/ Graffiti..like the gangs did in the 60's except instead of tagging " Eight Tray Gansgta's" all over a wall they would get their name out and make dope designs...
.....People began to do the shoutout style of rapping to the break music...which people began to cover with a new style of dancing called bboying, commonly confused as breakdancing.....You can tell its a houtout because they rhyme so slow and listen to the style even in Rapper's Delight...
.....Hip Hop began to evolve and soon there would be bboy battles, Dj's and even a rapper (and maybe rap battles) at Bronx and New York clubs....

It All took off from there....oh yeah the reason for the heavy influence of drums in hip hop is....watch the Discovery channel and see what the Africans ALWAYS play...

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