The show began performances Sept. 3 at Signature, which devotes 2003-04 to Irwin's works. It was to have closed on Oct. 26.

"Bill Irwin takes on the historic Harlequin character, the lewd and lazy rogue of commedia dell'arte," according to Signature. "With acrobats and live music, the play is a series of sketches that will parade the many shapes and forms of Harlequin before you with a nod and wink to tradition transformed with contemporary flair."

The work also features Irwin's longtime collaborator Doug Skinner and Marin Ireland, John Oyzon, Andrew Pacho, Rocco Sisto, Paxton Whitehead and Steven Williams.

What's unique about Irwin being the "signature" playwright this season is that he's the first non-traditional playwright represented by the company. That is, the average audience might not think of his movement and clown work as "texts" along the lines of the scripts of Arthur Miller, Romulus Linney and Lanford Wilson (who all have been Signature writers).

In addition to composing the show's music, Skinner will serve as musical director. Designers are Doug Stein (set), Catherine Zuber (costumes), James Vermeulen (lights) and Brett R. Jarvis (sound). David Gold and Sean McMorris are the show's musicians. Opening was Sept. 21.

Signature's Peter Norton Space is at 555 W. 42nd St. between Tenth and Eleventh Avenues. James Houghton is artistic director of Signature. For information, call (212) 244-PLAY. For additional information, visit www.signaturetheatre.org.