The style of flashy entertainment first made routine by Motown became the form of Soul music that dominated throughout the 1970s. Disco changed the beat, but not the basic show business emphasis on surface and form rather than content and meaning. At the same time, the values of "artistic expression" in Rock led to the era of superstar indulgence. Punk was the Rock music reaction to this trend and Rap was the Black music parallel to the Punk music. It began emerging at approximately the same time, although it took much longer to be discovered and publicized. Featuring interviews with Hip Hop...