By CHARLES McGRATH

On screen Catherine Zeta-Jones has been a famous smoulderer, a onewoman heat source. When Antonio Banderas unfastens her bodice in “The Mask of Zorro” - the 1998 movie that introduced her to most Americans, including her husband, Michael Douglas ? you feel he ought to be wearing oven mitts.

It was this quality, the sultry glamour she brings even to cellphone ads, that Trevor Nunn had in mind when he cast her as Desiree, her first Broadway role, in his revival of

“A Little Night Music,” which also stars Angela Lansbury and Alexander Hanson and opened at the Walter Kerr Theater on December 13. “A Little Night Music,” with music and lyrics by Stephen Sondheim and a book by Hugh Wheeler, is in large part about aging and mortality, and traditionally the part of Desiree, a famous actress at a turning point in her career, has gone to someone older than Ms. Zeta- Jones, who is 40 but looks younger. Glynis Johns was 49 when she created the role on Broadway and gave the part a hint of someone clinging to her past.

But Mr. Nunn said recently that a noticeably younger, sexier Desiree was important to his conception of the show, which ended its acclaimed London run in July.

“Everything of course makes sense when that’s the age group,” he said. “She’s at the point where she has to decide whether she still wants to be living out of a suitcase or whether she wants a life that’s more settled. But Desiree is pretty much the sex symbol of her age .”

The other thing Mr. Nunn knew about Ms. Zeta-Jones was that she was, as he put it, a “song and dance girl, a real theater animal.” For most Americans her Oscar-winning performance as the vamping, song-belting Velma Kelly in “Chicago” was a revelation, but in fact she grew up in the musical theater, and movie stardom came her way somewhat by accident. At 22 she was cast as a lead in “The Darling Buds of May,” a British miniseries, and overnight became so popular that, as she said, laughing, “I could never ride the Underground again.”

Recalling her teenage years in London, Ms. Zeta-Jones said: “I was a chorus girl. That’s all I ever wanted - to be onstage. I would queue up for auditions and then change my costume or put on a different leotard and audition again. It might take me two tries, but I always got the job. I figured out what they wanted.”

When Ms. Zeta-Jones was 5, her mother sent her to the Hazel Johnson School of Dancing, in the church hall just down the street, to channel her energy. At 9 she won a nationwide audition for “Annie,” and moved to London with a chaperone and a tutor. A t 19, cast as an understudy, she took over the lead in a West End production of “42nd Street.”

Almost ever since, she said, and especially after “Chicago,” she has wanted to return to the stage, but for one reason or another the right part never came along. She was hitting golf balls on a driving range in Canada last summer when Mr. Nunn called about “A Little Night Music.”

“He said, ‘Darling, I’d love you to do this, but I’m afraid I can’t use your dancing,’ ” she recalled.

She added: “There’s no jazzy hands, no high kicks, no fishnet stockings, but really that’s what excited me. With most musicals you have to fill in the gaps, but here you have what’s already a beautiful Chekhovian play, and the music is a bonus. The characterization is everything. ‘’

Ms. Zeta-Jones invests her part with a trouper’s energy and a joyful theatricality . “I’m just so happy to be there,” she said after explaining that because of Hollywood economics she wasn’t seeing many interesting movie parts these days.

“I feel at this point in my life I’m in my second chapter. You have to be quite frank with yourself. There’s that wonderful curve, and then this is the way it is: the second act. It’s great that now I can go back to my roots but in a completely different way.”

Alexander Hanson and Catherine Zeta-Jones in Trevor Nunn’s ‘‘A Little Night Music.’’ / SARA KRULWICH/THE NEW YORK TIMES; INSET, ETHAN HILL FOR THE NEW YORK TIMES