Chicago R & B legend Cash McCall is a singer in the great hard-soul tradition: his voice, rich in nuance and passion, is laden with the fervid intensity of gospel as well as a healthy taste of the blues. Born Maurice Dollison in 1941, he started out as a gospel artist (he played for a time with the famed Pilgrim Jubilees and also did a stint with the Five Blind Boys of Mississippi). In 1966 he achieved national recognition with "When I Wake Up," a jaunty mid-tempo soul number that stayed several weeks on the national R & B charts. These days he's best remembered around here as a session man, producer, and songwriter (among other memorable soul and R & B tunes he penned "That's the Way It Is" for Otis Clay), but he's retained the hard-edged emotionalism that informed the best of his soul recordings, and his style is a one-shot lesson in the history of local black music since the 1960s. He doesn't come back to town often, so this might be your only chance to see him for quite a while. Friday, 9 PM, Buddy Guy's Legends, 754 S. Wabash; 427-0333 or 427-1190.