By some indications this is, among other things, the decade of the keyboard romanticist. Richard Clayderman, in his first D.C. performance, a Washington Performing Arts Society concert, didn't fill Constitution Hall Saturday, as the shoeless George Winston does without even trying, but next time his gushing fans will doubtless line up around the block. Backed by a rhythm section of his compatriots and a dozen-strong string ensemble, all New Yorkers, the Parisian-born pianist offered a "West Side Story" medley, a whipped-up "Rhapsody in Blue" and numerous tunes from his hit list, including "Chariots of Fire."

Spreading his boyish charm with a yard-wide brush, garbling his English and racing through his French announcements, the tuxedo-clad Clayderman arched over his instrument and served up bare-bones melody seasoned by such devices as tinkling runs, pregnant spaces and two-fingered, woodpecker-rapid hammering. Shamelessly tearing pages from Victor Borge's book, the pianist and his synthesizer-playing conductor now and then indulged in warmed-over routines such as the "Oh, the sheet music is upside down" gag.

To Clayderman's credit, he did not pretend to be anything other than what he is, an evening's entertainment on the light and frivolous side.