Right down to the Roger Dean-designed sleeve, this five-CD box set overview of 1967-1976 progressive rock is as grandiose as the music itself, which is not necessarily an unconditional recommendation. But give the compilation points for diversity and thoughtful selection. The expected superstars (Yes, Genesis, ELP, Procol Harum) are usually represented by unexpected cuts that haven't been played to death on FM radio. A lot of ground is covered, from Krautrock (Can, Amon Düül II) and symphonic keyboards (Rare Bird, Argent, the Nice's "America") to the Canterbury sound (Caravan, Hatfield & the North) and pop hits with prog overtones (Traffic's "Paper Sun," Golden Earring's "Radar Love," Roxy Music's "Virginia Plain"). A lot of the Continental bands -- like Le Orme, Lard Free, Wigwam, Ange, and Samla Mammas Manna -- will be fuzzy or unfamiliar names even to progressive rock fans, making cult faves like Van Der Graaf Generator, Curved Air, the Pretty Things, Savage Rose, and Gong (all here as well) famous by comparison. Will the music cause those who dislike prog rock to re-evaluate their feelings? Absolutely not; the more accessible and poppy cuts are balanced by flashy instrumental workouts that -- as even the musicians themselves may admit -- do not exhibit a trace of humor. And no box that fails to include selections by Pink Floyd, King Crimson, Jethro Tull, Soft Machine, Kraftwerk, Mike Oldfield, early Brian Eno, and Kevin Ayers (in at least some cases for licensing reasons) can claim to be comprehensive. It is an interesting, carefully assembled, and extremely wide-ranging and catholic survey of the much-maligned genre. It's just a bit too much to take in all at once, and its very eclecticism ensures that many listeners (even dedicated prog fans) will feel the urge to skip around to concentrate on the subgenres they find most appealing.