Returning to the Kennedy Center Saturday night after an absence of only 10 months, Cleo Laine and the John Dankworth Quintet presented a well-received but uneven performance that contained excellance along with caricature and even sham.

The instrumental opening set was notable not for jazz, but for parody and novelty. "Tight Flight" paraded the obvious as it shifted jerkily from calm to gale. "Variations on the Paganini Theme" sadly attempted to revive the hoary "jazzing the classics" routine. Happily, veteran British vibraphonist Bill LeSage injected energy and swing into the otherwise bland proceedings with his tasteful feature number, "There Is No Greater Love."

Among Cleo Laine's assets are a commanding, even riveting, stage presence, an uncanny ability to project, and a voice that achieves impressive results on most kinds of songs. The finest qualities in her voice were displayed on the ballads "Send in the Clowns" and "He's So Beautiful."

A raucous "Born on a Friday" brought out the honky-tonk blues shouter in her and included a well-handled, stop-time passage on clarinet by Dankworth. On several numbers her voice became an instrument as she wordlessly jammed along with the now-energized quintet and traded fours with the leader on alto sax.

The evening had its high points amid the tedious and the shallow and was, admittedly, engaging as entertainment during Cleo Laine's part of the program. That leaves this to ponder: Jazz, a uniquely American art form, makes its way into the halls of the Kennedy Center seldom enough. Doesn't the homegrown product, the genuine article instead of the ersatz, deserve more attention by a national institution supported by public funds?