Jeff Stitely couldn't have asked much more of 1993, which brought the release of his quartet's debut album, critical acclaim, and even a brief European tour. Blame it all on hard work, and on a matter-of-fact iconoclasm that keeps this band fresh but prevents mere trendiness. As an example, consider the JSQ's unusual instrumentation: no piano, and a front line featuring John McLean's mercurial guitar and Ryan Schultz's bass trumpet (which offers more bite and clarity than its sound-alike cousin, the trombone). Yet the band's compositions exploit the possibilities of this mix without emphasizing its oddness. You could argue that as goes the leader, so goes the band. In his own drum solos Stitely offers plenty of thunder, but he ignores the petty flamboyance and predictable patterns that have given drum solos a bad name. Instead he concentrates on structure and form, and he and his band apply that approach to each piece in their repertoire, unveiling one impressive stratagem after another to burrow deep into their material. As a result, they consistently squeeze something new and often exhilarating out of tunes they've played a dozen times before. Drummer-led groups remain somewhat rare, and in the face of his success one could expect at least a modicum of envy among Stitely's fellow percussionists. Yet one of them has called his quartet "the finest jazz band in Chicago." During this weekend's performances they'll record for their next CD. Friday and Saturday, 8:30 and 10:30 PM, Jazz Buffet, 2556 W. Diversey; 862-0055. Sunday, Bop Shop, 1807 W. Division; 235-3232.