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 to combine 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 Jethro Tull...