Even among his countrymen–raging iconoclasts like Misha Mengelberg, Han Bennink, and Willem Breuker–Dutch keyboardist Cor Fuhler is a maverick. Conflating styles and disemboweling traditions, he takes the art of improvisation well beyond the playing. When he can’t coax or torture exactly the right sound from a conventional instrument, he modifies it or builds his own. On 7 CC IN 10 (Geest Gronden), his prepared piano is full of junk: objects like fishing line, bottles, and a box lid rattle around inside as he strikes keys and hammers strings with a mallet or vibrates them with an E-Bow. He frequently further alters those sounds in real time with tools like a digital delay unit, a distortion pedal, and a sampler. He’s also been known to push thumbtacks into the piano’s felt hammers–for a more percussive result–and to drop guitar pickups onto the strings to amplify the sounds in unexpected ways. On Bellagram (Geest Gronden), a recording by his trio with drummer Bennink and bassist Wilbert de Joode, he plays piano, chintzy organ, melodica, and keyolin–an invention that uses a two-and-a-half-octave keyboard to drive a bow across a violin. More recently Fuhler unveiled his comic side, releasing DJ Cor Blimey and His Pigeon (Conundrum), an amusing pastiche of easy-listening samples, Indian music, and hip-hop that allows him to play with his collection of esoteric keyboards. This week’s appearances, part of the Empty Bottle Festival of Jazz and Improvised Music, are his first in Chicago: on Wednesday, Fuhler will improvise with Jeb Bishop, Fred Lonberg-Holm, and Michael Zerang, and next Saturday he’ll meet up with Jim O’Rourke. Also on Wednesday–which is the opening night of the festival–German bassist Peter Kowald will make his long-awaited local reunion with Fred Anderson and Hamid Drake; for a preview check out Anderson’s Live at the Velvet Lounge (Okka Disk). Wednesday and next Saturday, May 13, 9:30 PM, Empty Bottle, 1035 N. Western; 773-276-3600. PETER MARGASAK