Rhyming on top of repetitive beats goes back to the dawn of human history, but Rap's year zero is commonly regarded as 1979, when the Sugarhill Gang released Rapper's Delight, which became a huge Hit. Hip hop more properly denotes the entire subculture into which Rap fits, since rapping is not a required component of Hip Hop songs. The major stylistic elements of Hip Hop music consists of MC'ing and rapping lyrics, DJ'ing and scratching records, dancing in styles like breakdance and street dance, sampling tracks, beat-boxing, and graffiti art.
Hip hop music in its infancy was an outlet and a "voice" for the disenfranchised youth of low-economic areas, reflecting the social, economic and political realities. It started as a DJ based phenomenon on the streets of the 1970's run down New York when block parties became increasingly popular in New York City, particularly among African American and Latino youth residing in the Bronx. In these block parties, DJs played popular genres of music, especially funk and soul music and began isolating the percussion breaks of popular songs. This technique was then common in Jamaican dub music. Because the percussive breaks in funk, soul and disco records were generally short, DJ Kool Herc and others began using two turntables to extend the breaks.
Turntable techniques for Rap music, such as scratching and mixing and matching beats, eventually developed along with the breaks, creating a base that could be rapped over, which is also taken from Jamaican dub music. Rap songs soon spread to be a nationwide, and later, a worldwide culture that put the MC, the Rapper, in front.
The mid 1980's to early 1990's are considered Hip Hop's "Golden Era" and are characterized by its diversity, quality, innovation and influence with strong themes of Afro-centricity and political militancy, with a strong jazz influence. By the end of the 20th century Hip Hop was perhaps the most influential music genre, changing the face of Pop culture forever, and spawning subsequent changes to R&B, dance music & Jazz.