Dutch improvisers Cor Fuhler and Gert-Jan Prins take improvisation to its logical end, getting creative not just with the arrangement but also with the production of sound. Both have spent years devising new instruments and technological mutations to make music with. Fuhler is still known primarily as a pianist, but he rarely tickles the ivories in any conventional manner. For his album 7 CC in 10 (Geest Gronden, 1994) he prepared his piano by filling it with junk: things like fishing line, bottles, and a box lid rattle around inside as he strikes the keys and strings. He further disfigured the instrument by inserting thumbtacks into the piano hammers for percussive effect and then treating his output with digital delay and distortion. On Bellagram, a trio recording with drummer Han Bennink and bassist Wilbert de Joode, he supplemented his piano with organ, melodica, and keyolin--an instrument of his own design that uses a two-and-a-half-octave keyboard to drive a bow across a violin. Gert-Jan Prins started out as a drummer in various industrial-tinged bands, but for the past decade he's focused on electronic noise. Last year he performed at the Empty Bottle with United Noise Toys, his duo with flutist Anne La Berge; in the unholy din they struck up, you couldn't tell who was making what sound. On Prins Live (Grob), recorded the same year, he went to town, unleashing dense clusters of white noise that bridged the gap between Merzbow's full-throttle attack and Pan Sonic's fragmented digitalia. And in many years working at STEIM, the prestigious electronic music center in Amsterdam, he's developed an intensely physical-sounding way of manipulating television transmitters. Since 1997 Fuhler and Prins have both played in MIMEO, a mini-orchestra of European electronics improvisers, and earlier this year they made their first record together, The Flirts (Erstwhile). It's a generous exchange of otherworldly, unidentifiable sounds; blasts of white noise, rippling electronic tones, artful clicks, milky hiss, scratchy static, and rumbling hums cavort in remarkably musical ways. Tuesday, October 9, 8 PM, Candlestick Maker, 4432 N. Kedzie; 773-463-0158. Wednesday, October 10, 10 PM, Empty Bottle, 1035 N. Western; 773-276-3600.