The notion that communal creation requires musicians to surrender their individual selves to the group for the good of the music is one you hear a lot in free-improv circles, but few combos put that ideal into practice like the European trio of reedist Urs Leimgruber, pianist Jacques Demierre, and bassist Barre Phillips. The group's sole album, the superb Wing Vane (Victo, 2001), sounds like a thoroughly collective endeavor--the empathy between these musicians is astounding, as evidenced by the way Leimgruber's squeaks fill in the spaces between the thwacks of Phillips's bass and Demierre's piano phrases. Whether crawling at a glacial pace, scrabbling about hectically, or indulging in one of their rare noise eruptions, these three seem able to consistently move as one even when they don't know where they're going. These vets occasionally employ some of free improv's trademark sounds and techniques--the reedist's overblowing, the bassist's scraping, the pianist's inside-the-instrument tinkering--but in surprising ways. I can never anticipate when a crescendo will suddenly drop away to silence, or when an assortment of seemingly unrelated puffs and whinnies will coalesce into a burst of richly textured color, but once they do I can't imagine things having turned out any other way. Saturday, May 3, 2 PM, Claudia Cassidy Theater, Chicago Cultural Center, 78 E. Washington; 312-744-6630. Wednesday, May 14, 9:30 PM, Empty Bottle, 1035 N. Western; 773-276-3600.