After his other band, the Sea and Cake, finished its tour with a show at the Beachland last fall, Tortoise's John McEntire immediately returned to his Chicago studio to work on a recording with loungy retro-futurists Stereolab. It was a typical end to a typically busy year for McEntire, a former Oberlin College student whose prolific output as a drummer, producer, and engineer makes him one of the most important figures in the (not so) underground post-rock scene that surrounds the Thrill Jockey label. Standards, McEntire's latest record with Tortoise, is his second major release for the label in the past several months, and already he's back on the road, beginning another tour where the last one left off. Tortoise, of course, has never followed the rigid, major-label-driven cycle of record-tour, record-tour. Instead, the instrumental quintet has opted for a fluid approach to its career. Like McEntire, the other members devote serious time to other projects, and they return to Tortoise without clearly defined roles or standard ways of operating. They take turns behind the instruments and at the engineer's desk, and this propensity for random reconfiguration shows up in the music itself. On Standards, loop-based rhythms and electronic ambiance meet prog-rock bass and jazzy vibraphone melodies, while harpsichord lines exist side by side with Moog noise. Each percussive piece is conceived as a remix. But Tortoise's overall aesthetic is restrained, favoring synchronization over soloing and subtle changes over outright wanking. Tortoise has already spawned a subgenre that encompasses everything from the techno jazz of Red Snapper to the edgy explorations God Speed You Black Emperor. And with other influential acts, like Sonic Youth, on radio's endangered-species list and apt to pass up Cleveland's limited experimental music audience, it's reassuring to know that sounds like these can still find their way here.