Why "The Odd Couple"? Hasn't everyone already seen Neil Simon's 1965 hit comedy on stage?

Apparently not.

"Everyone except the two stars, the director and most of the cast," answers Pittsburgh Public Theater's Ted Pappas, who's directing the revival that opens for previews tonight. And if he and his two leads have never seen it on stage, that must be true of much of the Public's audience.

But even for those who have, "it's a great American comedy with fabulous roles for the actors and exciting dialogue. It's a definitive play -- it helped invent a genre, the mismatched roommate comedy, that's held up for 40 years."

Pappas also points out it's the Public's mission "to present a diverse offering. We celebrate not only plays and performers, but the variety of playwrights. We've done three Alan Ayckbourns, for example, and many Shakespeares. I thought it was time to debut arguably the greatest 20th century American playwright -- certainly the most commercially successful -- in a deluxe fashion."

That's another reason to tackle a familiar play: to do it better than anyone else around here.

Pappas likens "Odd Couple" to the show with which he opened his tenure at the Public, the Kaufman and Hart staple, "You Can't Take It With You," another great American comedy.

He says its invention of iconic characters marks it as especially important. Whether played by Art Carney and Walter Matthau (Broadway), Jack Lemmon and Matthau (film), Tony Randall and Jack Klugman (TV) or two actors at your local straw-hat, fussy Felix and Oscar the slob are known to everyone, even if they've never seen the play, movie or TV show.

Pappas also relishes exploring the structure of "a classic three-act Broadway comedy. I find the New York ease of it exciting the way I find 'Guys and Dolls' exciting. ... In the '60s, Simon bridged the divide between TV and vaudeville and the new Broadway." In writing for TV's "Your Show of Shows" and his earlier Broadway comedies, Simon developed "elegant technique," enhanced by working with the original "Odd Couple" cast and "young genius" director Mike Nichols.

So Pappas classes "Odd Couple" not just with "You Can't Take It With You" but also "Born Yesterday," "Arsenic and Old Lace," "Harvey" and other classic American comedies.

He says the Public has approached the play as it should, as a new script. Even though "it will always have echoes of the great clowns who've played it ... I'm surprised how every single line feels new." It's still set in 1965, when a journalist could afford an eight-room apartment on Riverside Drive. And the Public has the added challenge of doing this picture-frame "box set" play on its thrust stage, which puts the audience right in Oscar's apartment.

"I imagine certain comedies can't ignite without the box, but this play is greater than that," Pappas says.

"Odd Couple" completes a season in which Pappas also directed "The Comedy of Errors" and "Amadeus" -- "pretty swanky," he calls it. "There are certain writers, real professionals of the theater, who you feel in the room with you, like Sophocles, Shakespeare and Simon. Their agenda is to wow the audience; their agenda is delight."

Pappas has wanted to do "Odd Couple" for several years, always with John Sherer as Felix. The CMU grad has previously appeared at the Public in "The History of the American Film" (1983), "Room Service" (1985), "By Jeeves" (2001) and "Broadway" (2004, directed by Pappas). He's also been back to Pittsburgh for the CLO ("Cabaret," "1776," "Tommy" and "Carousel").

Scherer says he and Pappas have talked about doing "Odd Couple" since they did "Broadway" in 2004. Last year, when Scherer was in "Love Musik" on Broadway, Pappas e-mailed, asking him to come do it this year -- his first time in a role for which he seems perfectly cast.

"I have the neuroses of Felix," Scherer says, "but I'm kind of a slob -- not dirty or careless, but messy." Oddly, his Oscar, Andy Polk, is actually very neat.

When Scherer finally sat down to read the play, he wondered if it was too dated, but he says now it isn't. "It's really funny. ... It may be the funniest play I've ever done." He says the trick is "to get out of the way of the play. I can't wait to get it in front of an audience" -- the ultimate judge.

A skilled comic actor with a face that breaks easily into megawatt smiles, Scherer says he loves coming back to Pittsburgh but admits to melancholy, too, faced with the sites of his youth. And of course there's darkness even in "Odd Couple," which begins with Felix feeling suicidal over the breakup of his marriage. He says his mentor, Ayckbourn, who directed him in "By Jeeves," said he would always sacrifice laughter for truth to character and getting an audience to care.

Although Scherer has never seen "Odd Couple" on stage, he has vivid memories of the TV show, down to a poem ("Ode to a Skyscraper") that Felix wrote in a writing course where a fellow student was played by Wally Cox. He can still recite it, because he and his brother used to audiotape TV shows, back before videotape.

Scherer recalls that he wanted to be an actor since he was 11 and performed in "Peter Pan" with Bonnie Franklin at the Studio Arena Theatre in his native Buffalo: "I found a place where I belonged." Pittsburgh is one of those places, too.