Onkyo, best known in the West as the name of a hi-fi company, is the Japanese word for "sound." It is also an umbrella term for a kind of computer music that is improvised, noise-based, and completely enthralling. Onkyo takes center stage at Japan Society tomorrow and Saturday in four-hour marathon concerts curated by computer-music pioneer Carl Stone.

"At this point, probably none of the artists associated with the onkyo style would use the term," Stone wrote by e-mail from Japan, where he teaches at Chukyo University. "Music evolves quickly, and terms become obsolete just as fast. Nonetheless, some of the hallmarks of onkyo would be radical abstraction, minimalist expression, and the challenge to musical idiom."

Stone's work bears out this description, ranging from a droning haze punctuated by silvery tingles to grinding, aggressively percussive tracks that might underpin extreme forms of rap.

As critic Alan Rich observed, Stone and his fellow computer musicians, sitting alone at their laptops, "can press a single key and unleash the combined might of a dozen symphony orchestras, a thousand-voice chorus, or the scratch of a toothpick across a napkin."

The music of Taku Hannoda, another marathon participant, typifies this vast expressive potential. It merges otherworldly whistles, unceremonious farps and sounds like temple bells—and whips up a riot of gnomic, jarringly spasmodic blips.

The dual nature of the word "onkyo"—exotic (for those unfamiliar with Japanese) and utterly generic—highlights essential qualities of the music.

Its hums and twitters are ubiquitous, part of nearly every soundtrack or pop recording a 21st-century listener is likely to hear, yet disconcerting in their purest form. Onkyo is at home everywhere and nowhere. Stone himself has recorded for both classical and rock labels, and audiences in Japan typically hear this music in clubs, although "listening very attentively, using concert-hall etiquette," Stone noted.

For the marathon, Japan Society will be set up as a club, with listeners free to wander as they please among various listening spaces.

In addition to Stone, Japan Society performers include Sachiko M, whose "austere and very beautiful work" is built solely on the sine tones embedded in her sampling keyboard. Downtown stalwart Elliott Sharp, too, often bases his music on algorithms and other scientific elements. Stone described Yoshimitsu Ichiraku's DoraVideo—a system of video-scratching using drums—as "loud, gregarious, hilarious and fun." Paris-based AOKI takamasa's music can weave together uneasy modulations, snippets of song, and nods to conceptual art, with one piece inviting listeners to "cover [their] ears."

Like dub, hip-hop and other forms of music based on sampling, onkyo calls into question Romantic notions of artistic originality. "Whoa—sampling versus originality—what a false dichotomy that is," Stone wrote. "In my view, sampling is the height of originality, because it creates the new out of the pre-existing."

As for another timeworn dichotomy—composition as opposed to improvisation—Stone's response again slipped through the philosophical cracks. "My performances are usually a blend of improvised details within a pre-composed structure. The performances at Japan Society will be entirely improvised, however."

Asked whether computer music represents a "posthuman" form of art, Stone replied: "The computer is an instrument that represents the technology of the day, just as the piano did in the 19th century. Let's remember, there are humans behind those laptops on stage."

WHEN & WHERE Onkyo Marathon, curated by Carl Stone. Friday and Saturday, 7 to 11 p.m. at Japan Society, 333 E. 47th St., Manhattan. Visit www.japansociety.org or call 212-752-3015.