A group like the Natto Quartet could only come from the Bay area. Where else could you find players who combine Asian consciousness, Western academic sensibilities, and improvisational acumen so effortlessly? Shoko Hikage's koto and Philip Gelb's shakuhachi represent the far side of the rim. Both convey a strong awareness of their respective instrument's history, but neither is bound by it. Pianist Chris Brown and electronicist Tim Perkis bring that Mills College sensibility; Brown plays well inside the box (prepared, of course) and out, dropping notes and clusters like a brisk rain into the broad spaces between breathy flute cries and stark plucked strings. Perkis generates machine hums and distorted insectoid rustlings that suggest a more than passing acquaintance with the ancient history of his instrument; watch where you step in that "Rainforest," folks. But what clinches it is the way they all hang together. The players sound so comfortable moving between sound worlds that they never trip as they cross boundaries.