Killer Joe Piro, dance-hall titan, demonstrates a new step at Shepheard’s discotheque in New York City in 1965. The discotheque had been born in Nazi-occupied Paris, as a place to hear recordings of banned American jazz and swing; it reached these shores in the 1960s and then soon mutated into that pure seventies phenomenon, disco. Disco’s white-hot flame of unfettered hedonism was bound to burn itself out, yet it left a permanent mark on the country’s social and cultural landscape—as Peter Braunstein explains inside.