Lynn Nottage has always been a darling of the nonprofit theater; she ever seems perched on the edge of breakthrough. While she has come close in works like the elaborately plotted "Intimate Apparel" and the memory-infused "Crumbs From the Table of Joy," a surfeit of artificiality often plagues her scripts, as if she were a perennial browser in literary fashion houses, addicted to trying on new styles.

It appears, however, with "Fabulation, or the Re-Education of Undine," Nottage may have at last found her true voice, and it is one laced with sardonic wit. The comedy is a bit unwieldy at times -- scenes and characters tend to repeat themselves quite a bit -- but her eye for the one-upsmanship rituals of fast-lane New York is unsparing and her ear for the misery of the down and out is acute. That she even strikes a rich vein in a scene set at a group therapy session for heroin users suggests a comic sensibility that is shifting into high gear.

The work is making its debut on Playwrights Horizons' second stage under the snappy direction of Kate Whoriskey. Nottage and Whoriskey were teamed up last year for the premiere of "Intimate Apparel" at Center Stage in Baltimore, and Whoriskey is to make her directorial bow with Shakespeare Theatre this coming season at the helm of "The Tempest." Greatly aided by an endearing central performance by Charlayne Woodard, as the Job-like Undine, Whoriskey's staging takes the full measure of all the bumps and twists in Nottage's story of a life in freefall.

As its title seems to imply, "Fabulation" is a spiritual descendant of "Absolutely Fabulous," the Britcom that punctures the pretensions of the fatuous founder of a boutique public-relations agency. (Undine almost sounds like an anagram for the name of the sitcom's main character, Edina.) The cruel brand of comedy in "Ab Fab" is mirrored in "Fabulation": Both revolve around the pleasures in watching a chic flack being taken down a peg. The difference is that by evening's end Undine has dropped off the pegboard entirely.

The target of Nottage's satire is the African American elite, an urbane class of achievers who attain the kind of material success that their parents could only dream of -- and who are running at full sprint away from their roots, a time-honored American tradition. Brooklyn-born Undine, it turns out, is herself a master fabulist, having changed her name from Sharona while at Dartmouth and telling her college friends that her parents had died in a fire. But a price has to be paid, Nottage asserts, for denying one's past; Undine is so busy making up her own life that she fails to recognize the dishonesty of others. Her comeuppance is at the hands of her dilettantish husband, Herve (a superbly oily Robert Montano), who runs off with her money, leaving her jobless, pregnant and homeless.

Nottage devotes too much attention to tying up extraneous ends; no part is too small for an extensive dialogue, and as a result we bog down in exposition, in overlong encounters with grannies and Yoruba priests.

Still, she derives sharp comic mileage from the downward spiral, particularly in an episode in a welfare office, where high-and-mighty Undine meets her match in the public servant (a spot-on Myra Lucretia Taylor) behind the plexiglass window. A total of eight actors play more than 30 parts; among the best are Stephen Kunken and Daniel Breaker (a standout last season at Shakespeare Theatre), both fine in an assortment of supporting roles.

Woodard's unfailing aplomb makes her an irresistible Undine. She shows how easy it can be to love a liar. The beauty of her performance is that you revel in both Undine's sense of entitlement and in the stripping away of it.

The charge the actors get in a new play like "Fabulation" has a lot to do with constructing a character from the ground up. On other New York stages, actors in long-running shows are asked to rebuild a portrayal from existing foundations. This was the formidable task facing Michael McKean and Carly Jibson, who have replaced the Tony winners Harvey Fierstein and Marissa Jaret Winokur in the hit musical "Hairspray."

The newcomers have altered the chemistry of "Hairspray" in a major way. This is not altogether a bad thing; McKean, a brilliantly subtle practitioner of comedy verite in Christopher Guest's pseudo-documentaries ("A Mighty Wind," "Best in Show") brings a sweetness to Edna, the plus-size laundress first played by Divine in the John Waters movie. He sings nicely, too, and at last you can make out all of Edna's lyrics. But a star like Fierstein leaves a wide wake, and McKean does not have the outsize force of personality to make his own waves (nor, perhaps, Fierstein's rock-solid belief in his own maternal instinct). The character, while appealing, is now another member of the ensemble.

More than ever, the show belongs to Edna's daughter, Tracy, and the adorable Jibson rockets through "Hairspray" full throttle.

She's younger and friskier than Winokur, and so Tracy 's hormone-fueled paroxysms seem funnier. When she falls hard for the high school heartthrob Link Larkin (Richard H. Blake), the words of Tracy's "I Can Hear the Bells" do not feel metaphorical. At any moment you wonder whether Jibson herself might start to chime.

Fabulation, or the Re-Education of Undine, by Lynn Nottage. Directed by Kate Whoriskey. Sets, Walt Spangler; costumes, Kaye Voyce; lighting, David Weiner; sound, Ken Travis. With Saidah Arrika Ekulona, Melle Powers, Keith Randolph Smith. Approximately 2 hours 20 minutes. Through July 11 at Playwrights Horizons, Manhattan.

Hairspray, music by Marc Shaiman; lyrics by Shaiman and Scott Wittman; book by Mark O'Donnell and Thomas Meehan. Directed by Jack O'Brien. Choreography, Jerry Mitchell. Approximately 2 hours 30 minutes. At Neil Simon Theatre, Manhattan.

Charlayne Woodard, above, stars as Undine in the play at Playwrights Horizons in New York. The strong cast includes Daniel Breaker, below left, and Stephen Kunken.From left, Daniel Breaker, Charlayne Woodard, Keith Randolph Smith and Saidah Arrika Ekulona in "Fabulation."