Still best known for his lifetime membership in the Art Ensemble of Chicago, multireedist Roscoe Mitchell has had a fascinating career on his own. Just a few weeks ago at the Bop Shop, his playing fit seamlessly into the riveting piano hard-bop of longtime cohort Jodie Christian, while some of Mitchell's recent work has found him fronting a dynamic combo with three percussionists and a pair of bassists. He's placed himself in many different configurations over the years, bold to any and all challenges, but one of his best situations is the solo concert. Like many to come out of the AACM, he exploits the possibilities of silence and space in his music, and this approach is rarely more evident than when he plays alone. While Mitchell can spit out a furious stream of heavily textured wailing, he often opts instead for a kind of meditative spell casting, his breathy, quiet, slow-moving lines tracing shapes of sound. What you don't hear can often mean as much, or more, than what you do. Friday, 9:30 PM, HotHouse, 1565 N. Milwaukee; 235-2334.