James Brown, the Hardest Working Old Man in Show Business, still won't quit until his audience is as wilted and battered as he is. His voice barks and croons as authoritatively as ever, he's got a female dance line to take up the slack when he needs a breather, and his band--if not up to the level of the Maceo Parker/Fred Wesley-led aggregations of yore--still lives up to Brown's unyielding standards: whatever they do, it's got to be funky. Ex-Temptation Dennis Edwards has reemerged from obscurity with a challenging and sophisticated blend of southern soul passion, vintage Motown slickness, and post-70s urban-contemporary romanticism. In a rational world he'd be a star; in the real one, he's having trouble getting airplay--commercial playlists are inflexible, and public and college radio blues and R & B shows remain mostly mired in historicity and purism. J. Blackfoot, though, may be the show's sleeper: best known for "Taxi," a sublime and tender ballad from 1983, he's a powerhouse on stage, bringing a gospel fervor to ballads and ravers alike. If there's still a state of the art in deep soul, J. Blackfoot comes close to representing it. Also on the bill are Bobby Womack and Shirley Brown. Wednesday, 8 PM, pavilion, University of Illinois at Chicago, 1140 W. Harrison; 413-5740.