When the quartet Oregon formed in 1973--as an all-acoustic offshoot of the Paul Winter Consort, whose resistance to serious improvisation had become confining--it offered listeners an unlikely alternative to the jazz fusion then raging around them. The group blended not just jazz and rock but also chamber music, folk, and the percussive traditions of India and Africa into what has become an indelible body of work. Still, no one would have guessed that its delicate, clockwork complexity would emerge as the longest-lasting survivor of that period: Oregon has weathered not only the passing of fusion but also the tragic death of its founding percussionist, the solo careers of its members, and the intrusion of synthesizers. On last year's Northwest Passage (Intuition)--the ensemble's best album of the 90s and one of its best, period--former Chicagoan Mark Walker splits the percussion work, and he'll return to town for the band's second local appearance this decade. Even Walker's most straightforward jazz work has echoed world-music rhythms, and his light touch belies the substantial voicings he brings to Oregon's music. The band's trademark timbre--Paul McCandless's sweet-and-sour oboe interlaced with the thick, brittle chords of Ralph Towner's 12-string guitar on arioso melodies from Towner's prolific pen--remains as expressive as it is unexpected. But McCandless has evolved into quite a strong player on several other reeds; blowing a dervishlike soprano sax and a provocative and spooky bass clarinet, he's steadily expanded Oregon's tonal palette. And bassist Glen Moore's separate projects have further illustrated his ability to summarize the musical information around him and sculpt it into the simplest of supporting frameworks. When the four of them crank up their fastest tunes, with rushing melodies and exploding colors, they still gather the momentum of a waterfall. Saturday, 10 PM, Martyrs', 3855 N. Lincoln; 773-404-9494. NEIL TESSER
Art accompanying story in printed newspaper (not available in this archive): uncredited photo.