1970s - The early years of Hip Hop
1970
Spoken word collective The Last Poets release their debut recording. Mixing politically conscious poetry with music, it later is lauded as an early progenitor of hip-hop.
1973
Clive Campbell, a.k.a. DJ Kool Herc, DJs his first party in the South Bronx, an impoverished neighborhood riddled with gang violence and isolated from the rest of New York City following the construction of Robert Moses’s Cross Bronx Expressway. Known as the father of hip-hop, Herc was the first to experiment with breakbeats, manipulating the instrumental breaks of old funk, R&B and soul tracks to form the basis of hip-hop.
1974
Influenced by Kool Herc, hip-hop pioneers Afrika Bambaataa, Grandmaster Flash and Grandmaster Caz start DJing at house and street parties across the Bronx.
Bambaataa forms the Universal Zulu Nation, a socially conscious collective of DJs, graffiti artists and breakdancers that included the b-boy crew the Shaka Zulu Kings. He defines the “four elements” of the nascent hip-hop scene as DJing, breakdancing, graffiti art and MCing.
1975
Grandmaster Flash starts mixing, a new DJing method that connects bits of two different songs during the breaks.
The first MC team, which stemmed from party shouts during DJ sets, is formed by Coke La Rock and Clark Kent, a.k.a. Tyrone Smith.
DJ Grand Wizard Theodore accidentally invents “scratching,” or nudging a record under the needle during breaks.
1977
Hip-hop spreads beyond the Bronx and into all five boroughs of New York City. Meanwhile, disco continues to dominate the radio airwaves and the club scene.
More rappers begin performing as MCing starts to eclipse DJing.
Bronx b-boys JoJo and Jimmy D form the Rock Steady Crew.
1979
Record label owner Sylvia Robinson assembles the Sugar Hill Gang, who record the first commercial rap recording, “Rapper’s Delight.” Written by Grandmaster Caz and featuring a sample from the disco act Chic, it exposes many Americans to hip-hop for the first time.
Kurtis Blow, managed by Russell Simmons, becomes the first rapper to sign with a major label. He releases “Christmas Rappin” on Mercury Records.
Hip-hop further enters the mainstream with Mr. Magic’s Rap Attack, a new Saturday night radio show on New Jersey radio station WHBI.
Wendy Clark, a.k.a. Lady B, one of hip-hop’s first well-known female artists, releases “To the Beat Y’All.”
Source: http://www.pbs.org/independentlens/hiphop/timeline_1970s.htm