Sound-Collage Partners, Mixing Stunts and Spirit.

Before firing up their decks at the McCarren Park Pool in Brooklyn on Thursday night, DJ Shadow and Cut Chemist cleared the stage for an instructional film, projected onto two backdrop screens. Beginning with a brief history of the 45-r.p.m. record, the film moved on to the logistics at hand. ''All audio is being delivered via vinyl on eight turntables into four mixers,'' a voice declared, in the plummy tone of a 1950s studio announcer. That may not sound like an applause line, but at this show it drew exuberant cheers. DJ Shadow (a k a Josh Davis) and Cut Chemist (Lucas MacFadden) have carved out an unusual niche together over the last decade, as sound collagists strictly devoted to the spinning of original-pressing 45s. The imposing challenge of such a task -- the records are small, and they spin quickly, so split-second coordination is critical -- imbues their live performances with a measure of daredevil sizzle. And their current tour, featuring a roughly hourlong mix called ''The Hard Sell,'' multiplies that factor in both substance and appearance: along with those eight turntables (twice the usual number), there were multiple video feeds, including the quick-lurching vantage from a pair of wristband cams. [ABSTRACT FROM PUBLISHER]