This is the first authoritative study of the music and history of progressive rock, a genre praised for its virtuoso instrumental solos and gargantuan stage shows, but also criticized for its privileged, upper-middle class roots. By using an interdisciplinary approach that draws together cultural theory, musicology, and music criticism, Macan illuminates how progressive rock - which includes bands such as King Crimson, Emerson Lake and Palmer, Yes, Genesis, the Moody Blues, and Pink Floyd - served as a vital cultural expression of the counterculture of the late 1960s and 1970s in England.