Natto Quartet creates beautiful sounds. The four-piece ensemble -- Philip Gelb, shakuhachi; Shoko Hikage, koto; Tim Perkis, electronics; Chris Brown, piano -- play a delicate, Japanese-inspired brand of free improvisation, emphasizing an intelligent use of space and subtle manipulation of sonic elements. Gelb's work is extraordinary. In utter control of the notoriously difficult bamboo flute, he's capable of producing an infinte range of timbre. Brown has a classical pianist's sense of touch and dynamics and a liberated way with melody and harmony. Hikage is an impulsive, expressive improviser; her work adds dissonance and a welcome percussive element.

Perhaps most impressive is Perkis' use of electronics. It's unclear exactly how he produces his sounds (I suspect he designs his own digital signal processing setup using a program such as Max/MSP or AudioMulch). Regardless, his contribution is both wonderfully complex and the most singularly human of any electronic music I've heard. The band's aesthetic is nonidiomatic but leans more toward classical than jazz. Their interplay is at times playful, meditative and even angry but always focused and intense. Exceptional stuff.