Percussionist and composer John Hollenbeck is a relentlessly multi-faceted musician who moves with ease between the worlds of classical, jazz, avant-garde, and progressive rock. Many know him as the creative leader of the Claudia Quintet, an innovative small ensemble whose music is as enjoyable as it is iconoclastic. In the past few years, besides leading his own big band project, Hollenbeck has also worked with artists as diverse as Bob Brookmeyer, avant garde vocalist Theo Bleckmann, Klezmer virtuosos David Krakauer and Frank London, avant-garde composer and performance artist Meredith Monk, and the unclassifiable pianist Satoko Fujii and trumpeter Natsuki Tamura (in their co-operative 'Junk Box' Trio). Rather than spreading himself too thin, this wide stylistic embrace seems to feed Hollenbeck's creative fires.

"Rainbow Jimmies" is more about Hollenbeck the composer than it is about Hollenbeck the drummer, or Hollenbeck the jazzman. Though the CD features a variety of different groupings - from violin / vibraphone duets, to percussion and saxophone ensemble works, to two pieces for the Claudia Quintet - "Rainbow Jimmies" comes across as a tightly conceived whole, rather than a collection of commissioned odds and ends. The seven Gray Cottage Studies, which constitute part of Hollenbeck's Guggenheim Fellowship project, were written for violinist Todd Reynolds (you may know him from his work with the Yo-Yo Ma's Silk Road Project and the New Music ensemble 'Bang On a Can'). Reynolds, whose violin playing here is nothing short of amazing, is joined in a series of duets and trios by Matt Moran on vibraphone, and by the composer on drum kit and vibes. Hollenbeck, in a brief liner note, mentions that the Gray Cottage Studies were written in a bucolic, pastoral setting. Hollenbeck, Reynolds, and Moran successfully capture an airy, open-ended, nature-centric sensibility replete with bird song, sun-dappled forest floors, and the silent gliding of a canoe on a fog-shrouded morning lake. At the same time, each study is based on a specific violin technique. Some of these techniques are quite apparent; the brief Study #3 is all about pizzicato, Reynolds' bow rattles over the strings like chattering teeth in Study #2, and dips across all four strings like a canoe paddle in still lake water in Study #1. The rather spooky Study #5 features very elongated and odd-sounding glissandi over Moran's vibraphone ostinato. The other studies are less obvious, violinistically, though no less rewarding. Hollenbeck joins the duo on Studies #4, #6 and #7, which have the same careful construction and rhythmic tension that is always evident in the work of the Claudia Quintet. Reynolds absolutely outdoes himself with a virtuosic and emotionally-charged solo over shimmering bowed vibraphones. I'd also add that there are some really beautiful and memorable melodies here - particularly on Studies #4 and #7.

The two pieces featuring the Claudia Quintet would not be out of place on any of their recordings, though it seems to me that, here, improvisation is somewhat de-emphasized, if not eliminated altogether. The maze-like, propulsive 'Sinanari' is based on a popular Turkish song that Hollenbeck dissected and reassembled into a totally new composition replete with odd harmonies, jagged rhythms, and high-precision ensemble passages. The title track - for me the pièce de résistance of the whole CD - opens with Hollenbeck's interpretation of the sound of jimmies - those little multi-colored sugary bits used to decorate desserts - falling on ice cream. The quintet (plus guest guitarist Mark Stewart - also from Bang on a Can) pull this marvelously humorous and fiendishly difficult device off with ease and grace. The action shifts continually, though my favorite part of the piece features a subversively twisted fuzzed-out guitar ostinato that resembles something Robert Fripp might write after spending the week with Anthony Braxton. Stewart's chameleonic guitar work fits in beautifully with the Claudia Quintet regulars.

The remaining pieces - 'Ziggurat (interior)' and 'Ziggurat (exterior)' are also quite tightly composed, and seemingly involve little or no improvisation. But both are brilliantly written and beautifully executed. As the titles suggest, both pieces are inspired by the processes involved in the construction of a shrine or sacred building. The result is a bit more literal than the other pieces on the CD - replete with restless, relentless clanking of miscellaneous metal and wood percussion and the rhythmic chanting of the workers. Here, Hollenbeck's interest in some of the repetitive and rhythmic devices explored by minimalist composers such as Steve Reich and Jon Gibson are most apparent, though the result is nothing like minimalism.

Amazingly diverse and ceaselessly fascinating, "Rainbow Jimmies" is an essential document by one of America's most inventive and original composers, and a must-have recording for fans of Hollenbeck's Claudia Quartet.