Clad in black leather and sporting a Mohawk, Kasper T. Toeplitz strikes a badass pose onstage, and his music backs it up. At his first Chicago concert in 2001, the Warsaw-born, Paris-based composer, bassist, and computer musician premiered Yam Almost May, a throbbing yet lyrical drone piece by Phill Niblock composed from samples of Toeplitz's bass, and the low frequencies seemed to hit listeners' guts as hard as their ears. For last year's Capture (released on Toeplitz's label, ROSA, an acronym for "Recordings of Sleaze Art") he captured the movements of three dancers via webcam and electronically translated them into sound, generating a slowly accumulating onslaught of flickering high tones and ear-scouring hiss. For this show he'll perform the U.S. premiere of Elemental II by Eliane Radigue, a French septuagenarian who's an unlikely collaborator for Toeplitz. Her detailed, gradually evolving electronic works evoked a meditative state even before she converted to Buddhism three decades ago, and she had never written a piece for another musician to play live. But Toeplitz successfully melds their disparate sound worlds on his recording of the piece. He first weaves a surface of coarse, frayed fabric, then pulls out intricate patterns of radiant, glassy pitches; about a half hour into the 50-minute performance a steady stream of wavering, ascendant sweeps, sounding more like bowed violins than bass guitar, escape like jets of steam from deep within the earth. Once the pressure's relieved, the piece resolves into distant groans, as if Toeplitz had made a field recording of shifting tectonic plates. Toeplitz will also play three of his own compositions. Sat 3/25, 9 PM, 6Odum, 2116 W. Chicago, 773-227-3617, $12. All ages.