In the pop music world, it's not at all unusual for a very popular or highly influential band to release a collection of outtakes, rehearsal tapes, previously unreleased live tracks and other odds and ends. In the bluegrass world, it's almost unheard of. But Doyle Lawson is a figure of such stature, and his band Quicksilver has been (in its various configurations) such a constant and powerful presence on the bluegrass scene, that this two-disc, 50-track collection of rehearsals, live tracks and other curiosities will probably be welcomed by the bluegrass marketplace without a second thought. And so it should be: Lawson's rejects are better than most bands' final versions, and it's surprising how clean and polished most of the rough rehearsal recordings collected here are. Inevitably there are some clunkers, and there are a few live instrumental snippets that are really too brief to be worth including. But some of this stuff is simply spectacular: a lovely rendition of the Canadian fiddle tune "Northern Lights," thrilling settings of gospel classics like "Ezekiel Saw the Wheel" and "Jezebel" -- even some of the throwaway novelty numbers like "Polka on the Banjo" and "Tennessee Banjo Man" pack a surprising amount of wallop. This set isn't the place to start if you're just getting acquainted with Lawson's deep and impressive catalog, but it's a must for established fans.