Rapper's Delight by Sugarhill Gang is probably the first time "hip hop" was played on the radio airwaves. Before then I'd say that it was just heard locally at parties and talent shows in the Bronx,Harlem, and Brooklyn.

Disco was still big at the time...so that overshadowed everything else...remember..the track for Rapper's Delight was a hit disco song that was still being played "Good Times" by Chic.