Few styles of popular music have generated as much controversy as progressive rock, a musical genre best remembered today for its gargantuan stage shows, its fascination with epic subject matter drawn from science fiction, mythology, and fantasy literature, and above all for its attempts tocombine classical music's sense of space and monumental scope with rock's raw power and energy. Its dazzling virtuosity and spectacular live concerts made it hugely popular with fans during the 1970s, who saw bands such as King Crimson, Emerson, Lake and Palmer, Yes, Genesis, Pink Floyd, and JethroTull bring a new level of depth and sophistication to rock. On the other hand, critics branded the elaborate concerts of these bands as self- indulgent and materialistic. They viewed progressive rock's classical/rock fusion attempts as elitist, a betrayal of rock's populist origins...