Lou Rawls had his work cut out for him at the Kennedy Center last night. He followed Deniece Williams, a pop phenomenon whose coloratura range is every bit as impressive as Rawls' luxuriant baritone.

Williams' voice consistently soared. Her ascents seemed effortless, yet remarkably controlled. One particularly demanding balled appeared to bring tears to her eyes; it also brought her a standing ovation as well as a bouquet of flowers from one of her fans. She was a hard act to follow.

Not to be outdone, Rawls made his entrance just as his 11-piece band reached a brassy crescendo and three leggy chorins launched the first of several Vegas-style production numbers. Rawls is so relaxed and engaging on stage, his voice so warm and confident, that it was easy to ignore the times when the Vegas trappings clashed with the material he performed, particularly "Dead End Street" and "Natural Man."

In fact, some of Rawls' finest moments came when he sang tunes associated with others, especially Stevie Wonder's "Sir Duke," Muddy Waters' "Hootchie Cootchie Man" and Nat King Cole's "Unforgettable." This is certainly the most polished and elaborate concert Rawls has ever staged in Washington and only occasionally did it obscure his considerable charm and talent. Williams and Rawls perform through tomorrow night.