One of American theater's most respected innovators, New Yorker Bill Irwin has been busy for weeks at the Philadelphia Theatre Company, creating a piece with eight performers, mostly Philadelphians. Together they have shaped

The Happiness Lecture

, a world-premiere comedy now in previews and opening Wednesday

.

"Who knows what's going to happen to this piece after a year? It's up to the gods," says Sara Garonzik, PTC's producing artistic director. She commissioned Irwin - a MacArthur fellow, a Tony-winning actor, and Sesame Street's Mr. Noodle - because she knew he and her theater both would benefit.

"The point is to do it, and do it here. What earns you an imprint in the national landscape is the production of new work," Garonzik said. "The best thing is to knock down the borders between New York and Philadelphia and have everyone working together."

Those borders are falling fast. While Irwin toils in Center City, Philadelphians have been making waves in New York. Sound and video designer Jorge Cousineau - who created stage effects for The Happiness Lecture - just won a Lortel, New York's big Off-Broadway honor. It came for his work on Opus, written by local playwright Michael Hollinger, premiered here by the Arden Theatre Company, and staged in both cities by Terrence J. Nolen, the Arden's artistic director.

Last week Philadelphia playwright Quiara Alegría Hudes was nominated for a Tony for her script for In the Heights, Broadway's most-nominated new musical of the season. And Tobias Segal, a young Philadelphia actor who started at Mum Puppettheatre, was nominated for the coveted Drama Desk award for his current role in Manhattan Theatre Club's From Up Here. Although he didn't win last night at the ceremonies in New York, the nomination is an achievement for the 26 year old.

A steadily growing relationship between the two cities' theater worlds has blossomed and is now perennial. Philadelphia no longer operates in New York's shadow; it has its own obvious dynamic. Plenty of busy actors, directors, playwrights and stagecrafters work in one place and live in the other. Theater created in Philadelphia moves north to Manhattan, and vice versa.

Current examples abound. East Oak Lane's Hugh Panaro, who starred in Broadway's Phantom of the Opera, is back home in the lead in Walnut Street Theatre's makeover of Les Miz, opening Wednesday. Also in the cast is Broadway actor Paul Schoeffler - his third role at the Walnut this season. The high-paying, big-exposure Walnut is a plum gig for New York actors.

"You have to get to the Walnut's New York auditions really early in the morning," says Zakiya Young Mizen, a Downingtown native who lives in New York and currently appears in Broadway's The Little Mermaid.

The wacky musical Nerds, a hot ticket for Philadelphia Theatre Company in first full production last season, is slated for Broadway. In the other direction comes the Harold Arlen/Yip Harburg musical Jamaica, cut to almost-cabaret plotlessness when it opened on Broadway in 1957. The Prince Music Theater's version, which begins May 31, will be its first-ever full staging, and it comes as a result of Prince producing director Marjorie Samoff's New York theater connections.

Smaller companies are in on the action as well. Philadelphia's Pig Iron Theatre premiered its contribution to a cycle of works called 365 Days/365 Plays in New York last year, then came home to perform it here, too.

Long relationships

Philadelphia's theater community has been building relationships with New York for decades. Since 1984, what is now the Prince has developed dozens of world premieres and sent many on to Broadway. The Philadelphia Theatre Company's elegant 1995 world premiere of Terrence McNally's

Master Class

headed north and won the best-play Tony in 1996.

Even earlier, the city was a well-known tryout town for producers refining New York-bound shows until prohibitive costs and other routes to Broadway ended the practice in the '80s. Now Philadelphia's two dozen professional theaters are making this a different sort of tryout town - a place to create something new.

When the Arden's Nolen made his New York directing debut last year, "it was amazing how many people talked to me about moving to Philadelphia, how many people knew about the work here," he says. ". . . You're not going to become rich and famous working in Philadelphia. People are here because they can do good work that challenges them."

"Philadelphia is not an outer borough of New York; it's an alternative," says Margie Salvante, executive director of the Philadelphia Theatre Alliance, the umbrella organization that sponsors the annual Barrymore Awards. Salvante was education director of New York's Roundabout Theater before she moved here, drawn in part by the city's affordability.

"We live in danger of being in New York's shadow," she says, "but what's emerged is a vibrant theater community that shares in both directions. New York is so desperately competitive, the opportunities to take risks and invent are so minuscule, the stakes so high. In Philadelphia, people have the room and the support of the community to try new ideas."

Local theater lovers have proved themselves willing to experiment, especially if word of mouth is good. According to the Theatre Alliance, local companies sold more than a million tickets last season, not counting Broadway road tours.

We go to New York, too. The Broadway League, New York's commercial theater producers, says Pennsylvanians - mostly from the Philadelphia region - bought 553,000 Broadway tickets in the 2006-2007 season. That does not include theatergoers from the region's three South Jersey counties. Factor them in, and the figure probably is closer to 800,000.

A comfortable place

Philadelphia is a comfortable place for those who work in or train for theater. In addition to the respected university programs, companies run their own schools. Director Walter Dallas, himself a New York emigre, not only imported talent to Freedom Theater because he wanted actors from both cities to mix, but also sent off many students from Freedom's training program to work elsewhere, including Broadway.

The Prince Theater's Rainbow program for high schoolers does the same. Alumnus Gideon Glick of Merion - part of the original Broadway cast of Tony winner Spring Awakening - says, "In Philadelphia, an actor can harness talent and develop."

Steve Kuhel, who now works with the Philadelphia Shakespeare Festival, cites "the focus on art and sense of discipline, mixed with a knowledge of shared sacrifice" that prevails here and says actors make "clear business sacrifices" in order to work in Philadelphia.

But offsetting any downside is the region's big plus: its manageable cost of living.

"The beauty of Philadelphia is that the economics allow you to create work that's pretty offbeat," says New Paradise Laboratories' Whit MacLaughlin, "and still be able to have a house and a family and the things normal people look for in life."

This opportunity extends to stagecrafters. "A young designer who lives in Brooklyn and works on a very small budget has a chance to come here and work on a larger scale," says Blanka Zizka, the Wilma Theater's artistic codirector.

Another boost is the Live Arts Festival & Philly Fringe, which brings locals and imports together in a burst of often cutting-edge performance art for two weeks every September. Artists network, producers scout. Performer Thaddeus Phillips, a festival regular, saw his career take off when he moved here from New York.

"Philadelphia is an amazing place to make original work," he says, "and the Live Arts festival has become a fantastic venue to present the work and get it seen."

Getting it ready was more the point at a recent rehearsal as Irwin and cast honed The Happiness Lecture. During a break, he described meeting local artists in workshops four years ago when he starred in Philadelphia Theatre Company's Trumbo. He offered his take on the Philly difference.

"The interesting thing about Philadelphia performers is that they don't delineate - and de-limit - themselves here, the way they tend to in New York. We are actors, dancers - everything - more readily here."

Contact staff writer Howard Shapiro at 215-854-5727 or hshapiro@phillynews.com.