The Re-Birth Brass Band treat the New Orleans brass band tradition like a scratching hip-hop deejay treats recorded music: they mix and match snippets with an abandon that sometimes seems anarchic, but their sound is actually the result of a carefully thought-out strategy. True to their legacy, the Re-Birthers create a music whose essence is rhythm--Crescent City second-line march cadences filtered through the funky grease of contemporary R & B, with an underlying polyrhythmic complexity that harks back to the city's Afro-Caribbean heritage. The aural mosaics they create are layered in nature, rather than linear: instead of stringing together melodies or rhythms from diverse sources, the band builds music from the bottom up, laying parade beats over African percussion patterns and then stacking it with modern funk bass lines, 70s-era horn patterns, and free-form blasts of sound reminiscent of Sun Ra. Like a vintage traditional jazz ensemble or a Fat Tuesday parade band, the Re-Birth Brass Band use precision, technical virtuosity, and an encyclopedic knowledge of their heritage and craft to elevate listeners into a soaring, rollicking state of good-time celebration. Also appearing on this bill, presented by the Old Town School of Folk Music, are Beausoleil, Terrance Simien and the Mallet Playboys, and D.L. Menard and the Louisiana Aces. Next Saturday, January 2, 7.30 PM, Orchestra Hall, 220 S. Michigan; 435-6666 or 525-7793.