Bebop has launched few saxophonists as artistically vital as James Moody, who got in on the ground floor: he joined Dizzy Gillespie's band at the age of 21, when bebop itself was still quite new, and rose to his first successes within a few years. Bebop still lies at the root of Moody's music, and his growth as an artist concerns the mature flowering of those revolutionary seeds. The same spirit of adventure that first led him to bebop also pushed him to brilliantly reinvestigate the form, starting in the early 70s, and then to tinker with electronics in the late 80s, with mixed success. But to my ears, anything that gets in the way of Moody's heated yet ordered solos--and the pure pleasure generated by them--deserves and demands suspicion. Be forewarned: Moody's mood determines the course of any given set, which means you may hear somewhat more of his jovial shenanigans--both verbal and musical--than you really care for. On the other hand, every drop of serious music that falls from his horns makes you wish for ten more like it. Moody remains a demon tenor player, one of the most powerful of the boppers; his dynamic flute work takes the wraps off the instrument, canceling its more prevalent light-'n'-lovely image; and his alto saxophone can be either a locomotive or a Lorelei. In Chicago he'll work with drummer Wilbur Campbell, a contemporary, and two younger and scintillating virtuosos, bassist Larry Gray and pianist Mike Kocour. Tuesday through next Sunday, July 25, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.