"Sweet" may sound like the wrong word to describe something as gritty as Vernon Garrett's gospel-rich vocal imprecations, but rest assured: he makes some of the sweetest soul music around. His recorded output has been modest--he made some noise on the charts in 1969 with "Without You" and then again in 1977 with "I'm at the Crossroad (Pt. 1)"--but his recent work on the Ichiban label has begun to expand his reputation. His live shows--especially when he has his own band with him, as he will on this gig--remain masterpieces of emotion: his voice, thick as blackstrap molasses, wraps itself around lovelorn ballads and slice-of-life vignettes with equal facility, and his own passionate commitment to the material keeps the mix heated to a boil. Besides displaying great technical proficiency, Garrett honors the twin soul icons of musical heritage and personal dignity: as drenched with sexual fervor as his shows can get, he always retains a spirit of uplift, optimism, and--for want of a more cutting-edge term--basic human dignity. Saturday, 10 PM, Mr. G's Supper Club, 1547 W. 87th; 445-2020.