Turning a movie into a musical is one thing. But turning a beloved cult film like Diner into a musical? You risk a run-in with fans who can quote at length their favorite lines from the 1982 Barry Levinson slice-of-life opus. Diner devotees have a serious attachment to the comic, bittersweet guy talk between boyhood friends who are easing into adulthood over fries and beers.

The ardent following of the film, set in 1959 Baltimore, was on director-choreographer Kathleen Marshall's mind as she readied the musical adaptation of Diner for its world premiere Tuesday at Signature Theatre in Arlington, Va. It's onstage there through Jan. 25.

"When you have a movie that is as beloved as this movie is, there are people who can quote whole passages and have favorite scenes and favorite characters, so our challenge is to let it be the Diner that they know and love and yet give it a fresh perspective," Marshall said after a recent rehearsal. "So we're adding to it as well. It's not just the movie onstage; it's different and it's more."

Marshall has her own favorite scene from the film, which also is her favorite scene in the musical. Let's just say it involves a couple on a first date in a movie theater, enjoying a box of popcorn - until the young lady discovers there's a surprise in the box. (Can't get much more specific in a family newspaper.)

"It kills me every time," Marshall says, laughing.

Her other favorite part: simply watching the camaraderie among the actors, "the way the guys finish each other's thoughts."

"Especially the actors from New York," she says. "About half the cast is here away from home, which gives them a chance to bond in a different way - going out to dinner, hanging out. It naturally is bonding them in a way that fits this show perfectly."

As for what is "different" and "more" about the musical's treatment of the story? It doesn't just tell the guys' point of view. The lens has been widened by Sheryl Crow, who wrote the music and lyrics for the musical, and by Levinson, the writer-director of the film, who wrote the musical's book. He has "really deepened the female characters," Marshall says. "In the movie there were no scenes that one of the 'diner' guys wasn't in. Now, in the musical, we have several scenes that are just the women, and it gives you a whole other perspective.

"And Sheryl gives a voice to the women, and we hear their point of view when they sing."

In the movie, one of the girlfriends - the bride-to-be Elyse - is much talked about, but audiences never see her face. "Now Elyse is a wonderful character, very feisty and sassy and funny and smart, and we hear much more from her," Marshall says.

Marshall anticipates that theatergoers will have more to take away from the show than nostalgia for a more leisurely, pre-texting and pre-digital age. "I hope the specificity of the story will hopefully lead people to think about their own friendships and marriages," she says, "and how they connect with people."