Although some scholars suggest that the roots of rap music are in the tribal instrumental chants dating back thousands of years, most agree that it did not fully emerge as a music genre until the 1970s. It was created in direct response to disco.
Disco was the predominant musical genre of the 1970s. In the early 1970s, DJs began remixing disco tunes to emphasize certain instrumental breaks. By the late 1970s, those same DJs found disco stale. So they also began spinning old records to liven up tunes.
Two DJs in particular, DJ Hollywood and DJ Kool Herc are accredited with giving birth to modern rap. Added to this was the instrumental breakouts, and spinning was the rhyming talk performed by club and party MCs during the music.
The first true rap song to find commercial success was "Rapper's Delight" by the Sugarhill Gang in 1979. Throughout the 80s, rap continued to be closely associated with DJs and MCs. By the mid-80s, rap had become a popular genre with several commercially successful rappers as well as a show dedicated to it on the MTV network.
By the 1990s, various styles of rap uniquely attributed to the east and west coasts emerged, creating a rift between rappers.