Japan’s musical underground has long been a hotbed of extremism; whether performing pure noise, black magic rituals, or convoluted prog, artists like Merzbow, Keiji Haino, and the Ruins practice sensory overload as a matter of course. Now a new generation is heading in the opposite direction. Collectively known as Onkyo, or “reverberation of sound,” this movement emphasizes stillness; at its most drastic, as on guitarist Taku Sugimoto’s solo CD Italia (A Bruit Secret), the musician’s ultraminimalist gestures are tiny punctuation marks dotting broad blank pages of silence. Toshimaru Nakamura, another prolific Onkyo artist, started out as a guitarist, and on 1997’s Repeat (Cut), the self-titled debut from his duo with percussionist Jason Kahn, he used effects to transform his instrument’s signals into grainy electronic textures and birdlike peeps. But a year later, on Temporary Contemporary (For 4 Ears), Nakamura had discarded his guitar and begun playing his mixing board. By plugging the board’s output into its input, he manipulates feedback loops to create the tiny crackles, hums, organ tones, and high-velocity bass patterns of his latest solo album, Vehicle (Cubic). The cyclical structures of Nakamura’s solo pieces sometimes sound like Pole without beats (in fact Pole’s Stefan Betke mastered Repeat’s first two albums). But another side of Nakamura’s playing comes to the fore when he improvises with other musicians. He responds to Keith Rowe’s rumbling tabletop guitar on Weather Sky (Erstwhile) with tiny swirls that break up the AMM member’s sonic expanses like dust devils along the desert floor. And on Do (also on Erstwhile) he matches the brutally high-pitched sine waves of fellow Onkyo musician Sachiko M with his own eardrum-perforating whistles. When Nakamura recorded with Sugimoto and Chicago bass clarinetist Gene Coleman in Tokyo last June, he favored the harsher end of his sound spectrum, confronting the former’s lonesome harmonics and the latter’s textured multiphonics with fine-grained static abrasions and sustained piercing tones. The trio will reconvene for Nakamura’s Chicago debut, which is also the final concert of Sound Field 2002, Coleman’s annual experimental music festival. Thursday, October 31, 7:30 PM, ballroom, School of the Art Institute, 112 S. Michigan; 773-722-5463.