NEW YORK — The theater is strictly come as you are, so the audience attends in hardhats and grime-caked work boots straight from ground zero.

Search and recovery workers walk six blocks from the World Trade Center rubble to a happy oasis called Tribeca Playhouse every Monday night for a free, off-Broadway show reminiscent of the 1940s entertainment put on by the USO.

The audience members "are our troops. They're rebuilding New York from its devastation," said Jeff Cohen, the show's director. "They're our heroes."

The 75-seat theater is a far cry from the stage used at the trade center site, where dignitaries make somber proclamations and clergy preside over prayer services.

Here, laughter and music overshadow the echo of the roaring excavation machines in the smoking pit that has become a mass grave. Performers flash smiles and fake diamonds, replacing for a short time the pulverized reality nearby.

"This is a great escape for us," said David Contessa, who wore a white hardhat decorated with U.S. flags to a recent performance. He has worked 12-hour days for two months straight, underground, splicing severed telephone wires.

The "Stage Door Canteen" features well-known names from Broadway and comedy. Show folks, who typically have Mondays off, donate their time and talents. With scant time for rehearsal, they spend as little as an hour practicing their acts before the curtain rises.

The tiny playhouse offered big talent the night Contessa was there: Tony nominee Mary Testa of "42nd Street"; Darius DeHaas of "Rent"; and Joanna Glushak, star of "Les Miserables" and the upcoming Broadway show "The Sweet Smell of Success."

"You're working so hard to rebuild New York City — and you are the stars. We're here for you," singer Aisha DeHaas told the audience, often a mix of firefighters, police, Red Cross volunteers and other workers.

The evening's emcee was comedian Kim Cea. Dressed in tight, slinky black under rosy spotlights, she got the weary workers roaring, poking fun at cabbies and the Taliban.

Three women in black with faux diamonds — the "Swingirls" — harmonized oldies, accompanied by an out-of-tune upright, a guitar and drums. Over the craggy crowd drifted a velvet refrain, "I've got the world on a string," while boots tapped to the rhythm on scruffy wooden risers.

Karin Sanders, Ft. Lauderdale, Fla., arrived in a white hardhat, part of a group of American Airlines flight attendants working as volunteers serving food at ground zero. She has been spreading news of the "Stage Door Canteen" at the trade center site.

"First, they say, 'I can't go to the theater looking like this!' But I tell them, 'You don't understand, you don't have to go home to shower and change. Come as you are!" said Sanders.

For the first month after the Sept. 11 attacks, emergency command posts filled Reade Street outside, and the theater — a former warehouse — was dark.

The idea for the show came in a dream to Cohen, 44, whose usual role is artistic director of the Worth Street Theater Company based at the playhouse.

Now, with a star cast that changes weekly, the "Stage Door Canteen" is in its second month. Expenses are covered with a low-interest loan from the Alliance of Resident Theaters, an umbrella organization for small theaters, and a grant from the New York Community Trust.