The title cut of the Rempis Percussion Quartet's first studio album, Rip Tear Crunch (482 Music), kicks off with a honking R & B figure solid enough to riff on or even work into a finished song, but for this local crew it's just a starting point. They're committed to "total improvisation"--the shorthand term saxophonist and bandleader Dave Rempis uses for improv with no composed or premeditated elements--and the 28-minute "Rip Tear Crunch" demonstrates how expertly they can articulate a strong sense of organization and forward momentum on the fly. Rempis moves quickly from one melody to the next, peaking with a salvo of baritone sax shrieks that ripples over Anton Hatwich's dancing bass figures and a dense combination of rushing flurries and strict timekeeping from drummers Tim Daisy and Frank Rosaly. After Rempis drops out, the others weave a spacious lattice of grooves, then taper off to a hushed crawl; when Rempis reenters he's on alto, playing a melancholy line, then quickening into darting phrases that fly through arrhythmic brushed-snare figures like a swallow threading between rustling tree branches in a stiff breeze. This band is a great way to see both Daisy and Rosaly at their extroverted best--neither drummer is a slouch on his own, but here they egg each other on to spectacular heights. And though Hatwich is the only member who doesn't get a nod in the quartet's name, the ease with which he shifts from sparse bowed melodies to sturdy pizzicato vamps is no less crucial to the group's success. This concert closes their 16-date tour through Canada and the eastern U.S., and playing together every night is sure to have turned up the heat on their already combustible chemistry. The quartet will play two sets. a 10 PM, Hungry Brain, 2319 W. Belmont, 773-935-2118, donation requested.