In its initial vinyl form, Curved Air's debut album is one of the prog rock movement's most prized artifacts -- not for the music (for that, it goes without saying, is flawless), but for the picture-disc format which had never previously graced a 12" rock record. A glimmering of that sought-after magnificence lives on, of course, in the artwork which has graced every subsequent release, this Collectors' Choice reissue included. Sadly, however, no other attempt is made to replicate the original jewel; indeed, beyond a straightforward dub of the album, Air Conditioning's American CD debut is something of a disappointment. No bonus tracks, no liner notes, no remastering -- nothing, in fact, beyond one of the finest classical rock fusions of the age. Curved Air were an unwieldy beast at the best of times, an uneasy liaison between Sonja Kristina's rampant rock sensibilities and her bandmates' undisguised virtuosity. Keyboard player Francis Monkman, in particular, led the group into some genuinely uncharted territory -- it was he who named the group after a Terry Riley composition; he who consumed side two of each album for a series of wild experiments, most of which incorporate acoustic folk, free form jazz, and a hefty dose of Vivaldi. Not that this was a bad thing. Indeed, Air Conditioning rates among the great debut albums of 1970s rock, a hybrid whose breathless audacity stands in starkly good-natured contrast to the po-faced noodlings of the genre's other leading progenitors. Even in full, fanciful flight (the instrumental "Rob One" or the sawing discordant "Vivaldi"), you can hear the band enjoying themselves, as Darryl Way's violin soars to pitches unknown to rocking man, the immortally named Florian Pilkington-Miksa conjures brand new rhythms from his percussive arsenal and Monkman. Well, Monkman is as Monkman does, but even when you know what's going to happen next, a frill or a flourish still leaps out to surprise you. Kristina, meanwhile, possesses one of the most distinctive voices of the age, a virtue which is apparent from the moment she enters on the opening "It Happens Today." Hints of Grace Slick enter her delivery during the Airplane-like "Stretch," but it's a fleeting comparison. By the time you hit "Propositions," all echoed riffs and space age synth, Curved Air don't sound like anything else on earth. You do, however, notice how many subsequent bands sound a lot like them. AMG.