The disc opens with a 20-minute opus that segues cleanly from ominous Eno-esque ambiance to a pleasantly droning Can/Stereolab-style groove, from buoyant bottom-heavy dub to a circular keyboard riff reminiscent of Philip Glass, from a percussive melody that recalls Steve Reich's mallet-based pieces to a spaced-out soundscape of sequencer blips and beeps. Although most techno-heads stay rooted in the cool detachment of the studio, making push-button music for BPM-ravaged ravers, Tortoise are fueled by every human kind of chemistry that radiates a reserved sense of warmth, and propelled by an improvisational spirit that makes it refreshingly difficult to guess where the band are headed next.

-- Matt Ashare