If ever there were too much of a good thing, Progeny: Seven Shows from Seventy-Two by Yes is likely it. These seven complete shows on as many double-disc sets were recorded in Canada and the U.S. between October 31 and November 20 during the Close to the Edge tour. They are the "source code" tapes from which much of Yessongs was assembled. That said, these complete gigs are remixed and remastered from two-inch, 16-track recordings previously thought to be lost. (Yessongs was created from two-track mixdown masters -- each subsequent remaster has come from those tapes.) Drummer Alan White had been with the band just three months after taking over from Bill Bruford. Musically, however, he's claimed the chair by this point; his uncanny playing relationship with bassist Chris Squire is cemented. The sonic quality of these concerts and the considerable variation in improvisational and instrumental moments, banter, and sheer dynamic force from night to night -- remember, this set is for the hardest of the hardcore only; civilians and casual fans won't get it -- are well worth it. Producer Brian Kehew's technical notes detail the painstaking process of getting the best sound possible and recapturing the dynamic range that Yessongs lacked. Some of the tricks included re-recording Squire's bass through a '70s-era bass amp and layering it atop the original thin one to get the fat, nasty, proper balance that is a Yes trademark. They also (re)calibrated the Dolby level of each guitar, individual drum, vocal, keyboard, etc. track setting by ear because they had been set incorrectly in the first place. That doesn't mean that the sound is perfect. Occasionally one can hear bits of ambient buzzing, a little too much crowd noise in a few places, moments of brightness -- as in the Duke University performance of Steve Howe's solo guitar break that makes a medley of "Mood for a Day" with "Clap." But these are quibbles. For fans, this box is about representing the performance magic of Yes at an early peak. Jon Anderson is at full, soaring, angelic strength. Rick Wakeman's B-3 and synth playing are on point, his synths soaring and free of bloated excess. Howe, Squire, and White surprise audiences and one another nightly with their interplay and solos. Each of these shows does exactly that. Whether it's in the extended jams like "Yours Is No Disgrace" or the "Close to the Edge" and "And You and I" suites, or awe-inspiring renderings of "Heart of the Sunrise" and the driving hard rock prog of "Roundabout," Yes were firing on all cylinders. Progeny is what rabid fans want; it captures not only the band at its early, inspired best but prog rock too. The new sleeve art by Roger Dean (each set has a different illustration) helps make this deluxe set a necessity for the obsessed.