If you've heard of Trevor Dunn, odds are it's because he plays bass behind gonzo front man Mike Patton in Mr. Bungle and Fantomas, but he's also an accomplished jazz musician. He's worked with clarinetist Ben Goldberg and guitarist John Schott in the extroverted Junk Genius, and in 1997 collaborated with Goldberg and New York reedist Marty Erlich for the swinging, beautifully austere quartet recording Light at the Crossroads (Songlines). Since leaving his native California for New York in 2000 he's been playing in John Zorn's Electric Masada and David Krakauer's Klezmer Madness. His own group Trio-Convulsant splits the difference between Mr. Bungle's twisted rock and Goldberg's forward-looking jazz, mixing wide-open improvisation with speaker-shredding thrash and flicking between tempos and meters like a prog band. The group's 1998 debut, Debutantes & Centipedes (Buzz), with guitarist Adam Levy and Junk Genius drummer Kenny Wollesen, swung back and forth between abstract lyricism and pinpoint bombast with amiable confidence, but the current version of the trio--with guitarist Mary Halvorson and drummer Ches Smith--hurtles from heavy to weightless and back again so quickly it's hard to keep up. This approach isn't Dunn's invention, of course, but on the new Sister Phantom Owl Fish (released by Patton's Ipecac label) his band pulls it off with rare style and impressive improvisational rigor. And the trio shows its sensitive side to great effect with a pair of well-chosen covers: a noirish take on Andre Previn's "I'm Sick" and a version of Ellington's beautiful "Single Petal of a Rose" enhanced by the gauzy harp of Shelley Burgon. Labelmates the Melvins (see Spot Check) headline. Thursday, September 9, 9 PM, Double Door, 1572 N. Milwaukee; 773-489-3160 or 312-559-1212.