I wouldn’t have thought it possible for a world-class new-music ensemble to use only saxophone, accordion, and double bass, but that’s exactly what Poing does. Since forming in 1999 this Norwegian trio–saxophonist Rolf-Erik Nystrom, accordionist Frode Haltli, and bassist Hakon Thelin–has played more than 40 premieres of works by some of the planet’s most progressive composers, particularly from Scandinavia, China, and Japan. Poing’s flexibility makes it attractive to young writers: the players have conservatory-honed chops and a fluency with the sort of extended technique you’d expect from improvising musicians. Two of the five pieces on the group’s second album, this year’s Planet Poing (Jazzaway), were written by fellow Norwegian Maja Ratkje, a dazzling vocalist and noise artist who performs in Fe-mail and Spunk. Her compositions demand that the musicians keep an open mind: “Rondo Bastard Overture Explosion,” for example, twists the rondo form to integrate solo practice recordings made on Dictaphones into the live performance, a process that greatly enhances the texture and dynamics of the piece. Ratkje and Poing will perform together at this show, part of a brief U.S. tour. a 8 PM, Bond Chapel, University of Chicago, 1050 E. 59th, 773-702-8670. F A