Petula Clark -- the international film and recording star perhaps best known to American audiences for her mod-pop ditty "Downtown" -- helms the newly revised national tour of Sunset Boulevard , which has set up shop at the Merriam Theater through January 31. And given the questionable history of the musical version of Billy Wilder's acclaimed 1950 film-noir expose of Hollywood, Clark has her work cut out for her. Sunset Boulevard 's original leading lady, Patti LuPone, was trashed by critics and prematurely (and scandalously) removed from the London production. Later on, Glenn Close originated the role in Los Angeles and brought her performance to New York. But despite her previous Broadway musical credits, she simply couldn't hit all the notes, inadvertently stepping beyond high drama and into high camp. Subsequent divas Betty Buckley and Elaine Paige tackled the role of the faded silent-screen star with acting and vocal abilities to spare, but weren't big enough names to bring in the box office numbers.

Meanwhile, both the London and Broadway shows were handsome but costly productions, and after running for years, they both closed without recovering their costs. Even last year's national tour closed prematurely, unable to support itself under the bulk (and expense) of its enormous set and lacking the star-power needed to carry off the show. Clark, for her part, hopes to reverse that sorry trend.

Is it intimidating to play a character called "the greatest star of all?"

She probably believes [that], because she's been told that so long. But what she really is is deluded and unpleasant -- although I think Norma is possibly more likable in this production. Norma is probably one of the best roles ever written for a woman. It's certainly one of the hardest. When I first saw the show, I really didn't think the role was for me. When I discussed this with Trevor Nunn [the original director], who talked me into taking the part, I asked him what he thought I had to offer in the role. He said, "your vulnerability." I never thought about that before or noticed it. But I suppose that's what I bring.

Do you have a favorite song in the show?

"As if We Never Said Goodbye" is my favorite, because it's such a magical moment. When she returns to her environment, you see her come back to life. She probably became a monster because she missed the studio, her work -- missed that magic. That can happen. And when she goes back to the studio, she comes back to life.

-- M. Scott Mallinger