In the Bronx in the 1970s, DJs built new music from old records. Grandmaster Flash perfected the method. He played two copies of the same record and toggled between them, catching the same drum break each time.
The result sounded like a beat that never stopped. In 1981 he recorded “The Adventures of Grandmaster Flash on the Wheels of Steel.” Three turntables cut at least nine records into one track.