With a three-horn front line, Charlie Kohlhase has to work hard to keep his quintet's thick middle from turning to mud. But the Bostonian baritone and alto saxophonist is an ingenious arranger who's been compared to Mingus, and one listen to the band's 1991 debut, Research & Development, or better yet the newer Good Deeds (both on Accurate) demonstrates the fact. Also a member of the Either/Orchestra and the Mandala Octet, Kohlhase combines buoyant swing--ably handled by the rhythm section of John Turner (bass) and Matt Wilson (drums)--with a startling sense of musical quest, sectional compositions, and smart voicings. Passing references to trombonist Roswell Rudd, bassist Johnny Dyani, and saxophonist Sam Rivers in Kohlhase's liner notes let you know that he's interested in the urgent musics of the 70s, when free jazz's discoveries were being synthesized and restructured by architectonically oriented composers. Along with Kohlhase's compositions, which are full of heady fun as well as ample room to blow, the quintet plays tunage by Thelonious Monk, Sun Ra, and Duke Ellington. With its wide range of colors and forms and its diverse mixture of traditional and outre elements, this group should be of interest to anyone who appreciates the kind of ensemble jazz made by Ed Wilkerson's 8 Bold Souls. Saturday, 8 PM, Green Mill, 4802 N. Broadway; 878-5552.