The best instrument inventors know that in the search for sound-making materials, less is usually more. A single piece of metal foil can contain a year’s worth of music, and a coiled spring can be an overflowing cornucopia of sound. Even Harry Partch’s elaborate-sounding Spoils of War and Surrogate Kithara were actually fairly uncomplicated contraptions. I’ve yet to see Michael Vorfeld’s instruments–this is his Chicago debut–but from what I’ve heard, he too realizes the value of simplicity. A musician and visual artist based in Kassel, Germany, Vorfeld uses the instruments he devises to improvise music. Sometimes he works within groups, playing totally free in the octet Ensemble H or interpreting graphic notation in the Mux Trio; sometimes he works alone. On his 1995 solo disc, Sieben Freunde (Berslton), he bows, scrapes, slaps, and snaps springs and strings–as well as cymbals and other standard percussion devices–in a luscious, expansive 16-part audio collage. Vorfeld is above all decisive, organized, systematic. He doesn’t grope for all available sounds at once but rather structures his investigation with the vision of an urban planner; after listening, you feel a profound understanding of each sonic nook and cranny. Vorfeld will play one set of solo pieces, then improvise with oboist Robbie Hunsinger and fellow sound artists Eric Leonardson and Lou Mallozzi. Thursday, April 23, 9 PM, Xoinx Tea Room, 2933 N. Lincoln; 773-665-1336. JOHN CORBETT

Art accompanying story in printed newspaper (not available in this archive): uncredited photo.