Music historians got lucky with minimalism. While the visual-art crowd is still sorting out seminal minimalist painters and sculptors, everyone agrees that Terry Riley's In C (1964) was the "big bang of minimalism" in the music world.

Instigated by La Monte Young, spread to the West Coast by Terry Riley, and then popularized everywhere by Steve Reich and the relatively late-on-the-scene Philip Glass, minimalism immerses steady, almost hypnotic pulses into a Technicolor jungle of interlocking melodic cells. Comprising 53 short musical fragments that fit on a single page, In C can be performed by any size ensemble. Within a basic pulse, musicians play each fragment as many times as desired, and stop when everyone reaches the 53rd fragment. SIL2K member Stuart McLeod describes it as "the 'hippie drum circle' piece of Western classical music."

Indeed, this hybrid of composition and improvisation is perfectly suited for the SIL2K Ensemble, a Seattle-based collective known for its performances of John Zorn's COBRA and the sorely missed Monday-night series of experimental music at I-Spy.

"Our group is a cross-section of professional classical musicians, highly skilled improvisers, DJs, and rock musicians," McLeod explains. "A lot of '60s composers like Terry Riley were interested in inclusiveness, and In C embodies that ideal. Group improvisation not only builds a community of musicians, but exposes common elements in different musical styles and practices. It's more about creating beautiful and unexpected sound than [about] showing off your chops."

Opening this evening is the Oxygen Ensemble, the collective behind the recently aborted Oxygen Lounge, an experimental music series formerly held Mondays at the Rainbow. Both ensembles cap off the night with the de rigueur mammoth monster jam. CHRISTOPHER DeLAURENTI

The SIL2K Ensemble performs Terry Riley's In C on Wed June 12 at 9 pm at the Rainbow (722 NE 45th St, 545-2960).

chris@delaurenti.net