In the 1970s, disco dominated American pop music. Originating in nightclubs that featured record players instead of live bands, disco was a major stylistic departure from rock, and its rise to the top of the music charts signaled a cultural shift that some found threatening. Disco's roots lay in a gay urban subculture, and the artists who created it were largely African American and Latino. In the gay dance clubs where it flourished, disco was much...