"A Sondheim Evening" is a modest revue of theater songs -- 22 in all -- but there's no denying the prodigious gifts of Stephen Sondheim, the composer who wrote them. Performed by five singers and two pianists in a faintly surrealistic backstage setting at the New Playwrights' Theatre, they serve as an introduction to the brio, the intelligence and the versatility of the man who is responsible for some of the boldest achievements of the American musical theater.

Sondheim has never been a particular favorite of the mass audience -- he seems to be an acquired taste. But this revue, originally put together for the Whitney Museum's Composers' Showcase Series, offers a wide enough sampling of his wares so that even the uninitiated are apt to find their palates tickled.

It combines the familiar (the overtaxed "Send in the Clowns") with the not-so-familiar (the antic "Instructions to the Audience," which served as the introduction to a production of Aristophanes' "The Frogs," performed in the Harvard University swimming pool). Rousers from "Company" ("Another Hundred People" and "Being Alive") alternate with the more esoteric delicacies from "Pacific Overtures" ("Poems," "Someone in a Tree"). There are even numbers that were cut from "A Funny Thing Happened on the Way to the Forum" before it reached Broadway ("Echo Song" and "The House of Marcus Lycus").

Sondheim's work has certainly been more flashily anthologized in the past -- most notably in the Broadway revue "Side by Side by Sondheim." "A Sondheim Evening" goes about its business unpretentiously, largely dispensing with commentary on the assumption that the songs speak for themselves. Some of them do, although others probably would benefit from being placed in a more specific context. Still, if you don't go to New Playwrights' expecting to be knocked out of your seat, you are likely to be charmed and beguiled.

The chief beguiler is Ann Johnson, a handsome performer who, before she even opens her mouth, lets you know by her confidently ladylike presence that you are in sure hands. In "This Is Nice, Isn't It?," she can't quite bring herself to declare her love. She dances delicately around the admission, seemingly eager to make her feelings felt, but always backing off at the last minute from the fatal words. It's a charming exploration of reticence trying to overcome itself, and characteristic of the fine shadings that Johnson brings to all her numbers.

Brian Davis, on the other hand, scores by the very clarity of his voice and the straightforward simplicity of his emotions. He does beautifully by "Johanna" (from "Sweeney Todd") and in "Echo Song" provides the sweetly ingenuous echo to Karol Bennett's wistful inquiries about the course of true love.

Donning Japanese half-masks, Davis, Charles Williams and Elizabeth van den Berg contribute the second-half highlight, "Someone in a Tree." I'd forgotten just how extraordinary that number is. It recounts the signing of the treaty that opened up Japan to American imperialism in the 19th century. But the recounting is done by three characters who were tangential observers of the event -- a samurai, hidden under the floorboards of the teahouse where the negotiations took place; a young child, perched in a nearby tree; and a forgetful old man, who is none other than the aged incarnation of the child.

What they are examining with their fragmented memories and contrasting views is the relativity of history itself. Who else but Sondheim would consider that an appropriate subject for a musical number?

Every now and then, director Peter Frisch gets too tricky with his staging. "Another Hundred People" has van den Berg singing that hymn to the tumultuous life of the city as if she were wandering through a nightmare (or a wax museum). "The House of Marcus Lycus" aims for lusty comic effects and wildly overshoots the target. The show is more successful when it concentrates on Sondheim's lyrics and puts the cavorting aside.

It is Sondheim, after all, who is the real star here. Although he is often accused of being cerebral and chilly, "A Sondheim Evening" proves how personal and deeply felt his work can be. Roy Barber's musical direction is properly discreet. So is Russell Metheny's set, which, for reasons I can't entirely explain, evoked shades of Colette for me.

Curious, I admit. But somehow not inappropriate for this evening of multiple and fleeting moods.

A Sondheim Evening, music and lyrics by Stephen Sondheim. Stage direction by Peter Frisch. Musical direction and vocal arrangements by Roy Barber. Set, Russell Metheny; lighting, Dan Wagner; costumes, Jeffrey Ullman and Jane Phelan. With Karol Bennett, Brian Davis, Elizabeth van den Berg, Ann Johnson, Charles Williams. At the New Playwrights' Theatre, through July 26.