Maybe it's the space-age, headlong twang that wraps around the near-dub rhythms on "Solaris," but Isotope 217 sound like a band that has succeeded at slipping through the cracks in at least three musical categories. Percussionists Dan Bitney and John Herndon (famed for their work with Tortoise) give Isotope a mathematically complex rhythmic frame, and guitarist Jeff Parker plays a guitar that's the sonic equivalent of clarified butter. But he's a grinder, too, especially on the opened "LUH," which rips and contorts. Then there are the keyboards, burbling and gurgling and popping and bouncing, like some Stereolab session that has broken the pop code and interpolated minimalism, avant-garde electronics, and more. But esteemed jazzbo Rob Mazurek's here on cornet, too, giving a riffing jazz vibe to "Looking After Life on Mars" and inspiring a slow, almost balladic rambling on "Real MC's." Isotope's debut, The Unstable Molecule, might've promised an accurate, precise machine, but Utonian adds a high degree of unpredictability to the formula. --Andrew Bartlett