Just in time for the cool weather, guitarist Kenny Burrell hits town, and you almost wonder if it's just a coincidence. Burrell has taken an essentially cool approach to his instrument from the moment he came on the scene in the mid-50s and established himself as the guitar voice of hard bop. He seemed to have arrived at this stance by building up from the foundation of his exceptionally full, dark tone; to this he applied a rangy but unhurried harmonic curiosity and an ability to distill the complexities of bop into speedy, straightforward melodies that could fit such widely divergent styles as those of John Coltrane, Gil Evans, and Jimmy Smith. (Along with fellow guitarist Wes Montgomery and vibist Milt Jackson, Burrell helped lay the foundation for the relaxed funk groove that came to define jazz for many listeners in the 60s.) Burrell began to mellow in the 1980s, opting for more relaxed tempos and less propulsive ensembles and exploring older music (such as the songbook of Ellington & Strayhorn, which occupies a quarter of the program of his just-released Concord CD, Lotus Blossom). But he went further in that direction than made artistic sense, losing much of the drive that once provided the supple foundation for his swing and prevented his cool lines from getting cold: his tunes and tempos had a worn and tired edge, and I thought that Burrell sounded like a man trapped by his past. In recent years, though, he has entered a new phase of his career, in which he has grown into his own history: still mellow, he nonetheless attacks the music with renewed appetite, as if discovering these familiar patterns and connections for the first time. Best of all, his sense of intrigue proves infectious, making the music fresh for his listeners as well. Drummer Ed Thigpen, who joins Burrell for this engagement, shares this genuine if low-keyed excitement about jazz and the process of making it; it comes through in his thorough professionalism and the spry musical commentary he weaves in and around his crisp timekeeping. Chicago bassist Eddie de Haas rounds out the trio: his smooth lines and talc-dry tone serve to blend the other instruments, instead of out-booming them, which makes him an especially simpatico choice for Burrell. Tuesday (which serves as a CD-release party for the new album) through next Sunday, October 8, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.