This is how it worked: One guy, the DJ, played records on two turntables. One guy—or girl—served as master of ceremonies, or MC. The DJs learned to move the record back and forth under the needle to create a "scratch," or to drop the needle on the record where the beat was the hottest, playing "the break" over and over to keep the folks dancing. The MCs "rapped" over the music to keep the party going. One MC sought to outchat the other. Dance styles were created —"locking" and "popping" and "breaking." Graffiti artists spread the word of the "I" because the music was all about identity: I am the best. I spread the most love in the Bronx, in Harlem, in Queens. The focus initially was not on the MCs, but on the dancers, or B-boys. Commercial radio ignored it. DJs sold mix tapes out of the back of station wagons. "Rapper's Delight" by the Sugarhill Gang—the song I first heard at that face-slapping party in Harlem—broke the music onto radio in 1979.