It’s been years since Chicago came up with a major force in blues or R & B saxophone–west sider Michael Jackson might just be the one we’ve been waiting for. You might have heard him a few years ago on Somebody Call My Baby, an LP released by the late Johnny Christian on the Big Boy label: lithe and exploratory with a full-bodied tone, a rhythmic drive that never dragged, and a rocking sense of back-alley fun, he rode herd on Christian’s soul-blues vocals and brought an element of freshness to arrangements that otherwise might have seemed unimaginative. Jackson is that rare soloist who’s capable of doubling as a tasteful sideman: he fits himself into a prearranged section with uncanny synergy, and he’s got the self-confidence to wait until the right moment to exert his individuality and strut his stuff. As if that weren’t enough, he’s also an accomplished vocalist who fuses a funky contemporary urban sophistication with an enthusiasm for the primal intensity of traditional Chicago blues. This solo appearance could mark the beginning of a major blues career. Thursday, Rosa’s, 3420 W. Armitage; 342-0452.