If you are tired of seeing jukeboxes being passed off as musicals, if you long for intelligent repartee rather than the listless waving of semaphore flags, then you know where to go. William Finn, the composer of Falsettoland and The 25th Annual Putnam County Spelling Bee, may not be the biggest of Broadway names, but this celebration of his work is enough to restore anyone's faith in an endangered art form.

The man himself made a slightly reluctant curtain call at the end of an effervescent evening. A heavy-set, grey-bearded figure, he bears a passing resemblance to Oliver Sacks. His songs too remind me a little of Sacks's precise case-studies: passions and neuroses are sketched with the deftest of hands.

Directed by Andrew MacBean, the show gambols through Finn's urban landscapes. You could argue that much of the programme does not venture beyond more than six blocks of the Upper West Side, yet Finn delves into every nook and cranny, from the lower depths, where a destitute woman begs for small change, to the salons of the affluent and insecure.

It is a long time since I heard contemporary songs as ruthlessly witty as Poor, Unsuccessful and Fat or Four Jews in a Room Bitching. Gayness and Jewishness are, you see, two of Finn's recurrent themes. In lesser hands, it might all become cloying. Finn, however, possesses a wry sense of humour, and even if you sometimes detect shades of Sondheim, his melodies are crisp and vigorous.

Accompanied by the sure-footed pianist and musical director Matthew Brind, the cast rise to the challenge. Sally Ann Triplett transforms herself into a frumpish martinet of a music teacher on Only One. Louise Dearman's potent voice matches the emotional punch of Anytime, while the curvaceous Frances Ruffelle vamps it up gloriously on Stupid Things I Won't Do. Gareth Snook and Simon Thomas bring actorly depth to their roles. And the former Steps singer Ian H. Watkins, whom I last saw flailing around in that dreadful production of Fame - The Musical more than holds his own.