Hermeto Pascoal's place in Brazilian music has no single analogue in the States: he simultaneously occupies roles held at various times and places by genre-defying keyboardist Chick Corea, outsider composer Moondog, and ethnomusicologist Alan Lomax. Pascoal plays a variety of flutes, guitars, and saxophones as well as piano and accordion, all with dazzling wizardry, and as an improviser he's developed a characteristic style that transcends existing schools--in keeping with his wild-man image, he plays like a barely tuned spring, coiling and then flying loose but never quite coming completely unmoored. (A gnomish 68-year-old albino, he stands perhaps five foot five, with long, flowing white hair and an outlandish beard.) As a composer he's based his work on the music of his country's aborigines, creating a Brazilian jazz replete with through-composed melodies, open-ended structures, and jungle-bird timbres; its stark harmonies and ancient rhythms make the sleek sounds of bossa nova and tropicalia seem tame by comparison. Stateside listeners got their first taste of this stuff in 1970, after Miles Davis recorded two of Pascoal's short pieces for Live-Evil; later in the decade Pascoal reached American ears in a band led by two of the many musicians he's directly influenced, Flora Purim and Airto Moreira. Since then his few albums available here--the best of which is 1987's So nao toca quem nao quer (Intuition)--have provided glimpses of his evolution as a singular artist: only those he's mentored and inspired have made music even remotely like his own. This can't-miss gig is Pascoal's first in Chicago in more than a decade. Saturday 30, 6 and 9 PM, Old Town School of Folk Music, 4544 N. Lincoln, 773-728-6000 or 866-468-3401, $30, $26 seniors and kids. All ages.