, on its latest swing through town. Urick makes music on a laptop, and while that's not the most demonstrative instrument for live performance, there's no use at this point in repeating the usual critical cliches and jokes about laptop musicians. Needless to say, Urick seated at a MacBook isn't terribly exciting, and the odd film footage projected on the wall behind him didn't add much entertainment value. But listening to Urick basically create a lush bed of strange sounds in real time is still a pretty fascinating process, with humming layers of noise and churning rhythms slowly overlapping and building in volume and intensity. Tortoise gives you a bit more to watch onstage, but not much. The members of this cerebral instrumental quintet mostly hunch over their instruments, intensely laboring over complex polyrhythms and almost defiantly awkward grooves. When they finally took a break from those aggressive workouts for an older, jazzier tune like "I Set My Face to the Hillside," fans broke out in applause with both recognition and seeming relief. But when Tortoise committed to newer, less immediately appealing terrain, there was something perversely enjoyable about how uncompromising it was.