Unlike many rhythm and blues performers whose careers stretch back to the '50s, Etta James and Otis Rush remain intense, contemporary performers. James, who opened their show at the Wax Museum last night, proved that her powerful voice can still move from a kittenish purr to a lusty growl with just a twitch of her hips. Her full-bodied voice ranged over soaring blues ballads such as her own "I'd Rather Go Blind" and gospel-based rockers like "Something's Got a Hold on Me." Much of James' power lies in her experience. She brought the kind of wisdom, irony and humor to her music that transformed her love songs into passionate autobiography.

Otis Rush is probably the most active and vital practitioner of the electric Chicago blues. On stage, Rush carried an intense aura, supported by searing single-note guitar leads that occasionally gave way to jazzy improvisation reminiscent of B.B. King. Although lacking its usual authority, Rush's rough and passionate voice could still slide into falsetto cries and toss off gruff asides. Most of the talking, though, was done by the stinging, sustained notes Rush wrenched out of his Stratocaster. It was a disappointment, however, to see Rush, an artist with an impressive blues catalogue of his own, leaning on material like Albert King's "Crosscut Saw."