You never know what you’re going to get with Thomas Lehn. On recent recordings the German analog synth master has effortlessly adjusted to radically different contexts. In Konk Pack, his anarchic trio with drummer Roger Turner and multi-instrumentalist Tim Hodgkinson, he’s a dervish, frantically uncorking stabs, smears, and blasts. His approach on Dach (Erstwhile, 2001), a trio outing with trombonist Radu Malfatti and violinist Phil Durrant, is the polar opposite: the music is slow and barely audible, as Lehn carefully turns knobs and plugs in patch cords to create tones that fit perfectly with the acoustic rattles, scrapes, breaths, and thwacks of his partners. But it’s on his solo album, Feldstarken (Random Acoustics, 2000), that Lehn really cuts loose. His quick-moving abstractions have an almost 3-D quality as they assault both your ears and your gut, and his improvisations are full of unexpected twists. Rarely does a sound or tone linger longer than it takes for Lehn to set up the next (although on “Feldstarke 2” he reworks a soft high-frequency sputter for a full 15 minutes), and his catalog of sounds–squeals, booms, hums, and flutters–is immense. Although Lehn has performed in Chicago in several different groups (a duo with percussionist Gerry Hemingway and a stellar sextet with Axel Dorner, Johannes Bauer, and Chicago’s DKV Trio among them), this will be his first solo concert here. He’ll use some prewritten material–which may incorporate TV and radio broadcasts recorded during the first days of the war in Iraq–but most of his two sets will be improvised. Saturday, May 3, 9 PM, 6Odum, 2116 W. Chicago; 312-666-0795 or 773-227-3617.