Performances will end Jan. 31 at PH's Peter Jay Sharp Theater on West 42nd Street. The original engagement opened Oct. 13, 2009, to rave reviews that prompted two extensions through Nov. 21. Following a hiatus, and by popular demand, performances resumed Dec. 15 for a limited engagement through Jan. 17. The production will now extend two additional and final weeks.

The play cannot extend beyond the final date of Jan. 31.

A spare, comic and sad look at an amateur acting class, Circle Mirror Transformation has become one of the longest-running shows to play at Playwrights Horizons, and the longest-running production to play at the company in almost 20 years. It surpasses the original, extended runs of such acclaimed Playwrights Horizons hits as Grey Gardens, I Am My Own Wife, The Heidi Chronicles and Driving Miss Daisy.

The original cast continues: Obie Award winner Reed Birney, Tony Award nominee Peter Friedman, Obie Award winner Deirdre O'Connell, Tracee Chimo and Obie Award winner Heidi Schreck.

Here's how Playwright Horizons bills the play: "When four lost New Englanders enrolled in a Shirley, Vermont community center drama class experiment with harmless games, hearts are quietly torn and tiny wars of epic proportions are waged and won. Annie Baker's new comedy is a beautifully crafted diorama, a petri dish in which we see, with hilarious detail and clarity, the sweet sadness of a motley quintet." The production features scenic and costume design by David Zinn, lighting design by Mark Barton and sound design by Leah Gelpe. Production stage manager is Alaina Taylor.

The performance schedule is Tuesdays through Fridays at 7:30 PM, Saturdays at 2 PM & 7:30 PM and Sundays at 2 PM & 7 PM. There won't be a performance on Jan. 28.

Tickets, $50, may be purchased online via TicketCentral.com, by phone at (212) 279-4200 or in person at the Ticket Central Box Office, 416 West 42nd Street (between Ninth & Tenth Avenues).

Visit www.playwrightshorizons.org.