If you think you have a hard time picturing chirpy '60s British pop star Petula Clark as the ever-bitter, ever-desperate Norma Desmond -- how do you think Pet herself felt when asked to tackle the thorny role?

The 66-year-old Clark -- the magic voice behind "Downtown" and "I Know a Place" -- knew in her heart she wasn't right for the role and fought against taking it. At least until big-shot director Trevor Nunn convinced her otherwise, telling her she indeed had the stuff to make Norma smoulder.

Norma Desmond is the main character of "Sunset Boulevard," a classic 1950 Billy Wilder film in which Gloria Swanson stamped Desmond indelibly on the American conscience, barely veiling how close the role came to her own life as she deftly painted a jaded, faded silent movie star left behind by life,love and talking pictures. Swanson's Desmond, who dreams of a comeback with the help of a gigolo screenwriter, leaves behind a few lasting cinematic images, including the crazed actress's final descent down a grand stairway.

The film has since been turned into a big musical and a cottage industry for the West End wonder, Andrew Lloyd Webber. That cottage pulls in to Schenectady this weekend, as the touring production of "Sunset Boulevard"comes to Proctor's Theatre for five shows. Glenn Close made Norma a hot commodity again in November 1994, when she and Lloyd Webber brought the production -- with its requisite glitter, bombast and hydraulic moving parts -- to Broadway (following London and Los Angeles runs with Patti Lupone and Close, respectively). "I had seen the show on Broadway with Glenn Close and enjoyed it but I wasn't, well, blown away by it. The set was wonderful and all that but I didn't like the characters very much and I certainly had no desire to play it," says Clark.

Fate felt otherwise, or at least Trevor Nunn (Lloyd Webber's director of choice and partner in the Really Useful Company) did. "A few months later, I was on my way to holiday in France and I was called back into London, which is still sort of home, by Trevor Nunn. I had a pretty good idea what it was about. Anyway, we spent three hours together in the Really Useful offices in London and it was three hours of me saying 'no, no, no' and him saying 'yes, yes, yes.' I guess he was more convincing than I was, because the next thing I knew I was rehearsing Norma Desmond." Clark was 32 in 1965 when "Downtown" finally broke through in America for her. By then she already had racked up more than 20 films, including her 1944 debut in "A Medal For The General," and a dozen UK Top 40 pop hits. To date, she has more chart hits in Britain than any other female vocalist. She schedules her solo tours in Europe in between dramatic engagements, and fills in whatever free time she has left writing poetry, lyrics and even her own musicals -- like 1989's Civil War love story "Someone Like You."

Clark seems to be a bit of a reluctant theater star, and she told a very similar story about joining up with Willy Russell's' "Blood Brothers" in 1994 -- begging off before being egged on by her husband of 37 years, the French record producer Claude Wolff. Legend has it she was also reluctant to follow in Julie Andrews' footsteps in a 1981 revival of "The Sound of Music."

"The argument this time," Clark says, "was that I didn't think I was right for the role, and I was frankly a little bit frightened of it. I had never been asked to play something so far afield from myself before." "Blood Brothers" -- Clark's American "comeback' despite the fact that she's been a huge star in Europe since the age of 8 -- "was very different from this obviously, but it was a character that was easy for me to relate to. I found it very difficult to relate to Norma at first." "Trevor said, 'Listen to me, I don't want you to play Norma like it has ever been played before. I want you to play it your way, and I said, 'What's that?' because I couldn't see it at all." Nunn said she could offer a sense of humor and a vulnerability to the role -- and she ended up doing just that for a year and a half in the 1995 London production.

Clark said that, with time, she's moved even closer to Norma, despite their differences. "She crept up on me, I crept up on her, and we met. I have enormous affection for Norma now. I really like her. Obviously, I feel sorry for her. The great thing is to like her, though. I feel that's important. "I've talked to other actors who've played really monstrous people, really hateful people -- which I don't think Norma is -- and the actors have always said that you have to find something about the character that you like, and I think that's very true. "It's the first time I've played anybody like this, where I have very little in common with her, so I had to find something about her that touched me. Exactly what that is I can't quite say, I can't quite pinpoint, but it's there."

Clark now performs songs from "Boulevard" when she performs in concert, and even features three of the Lloyd Webber numbers on her new Varese Sarabande album, "Here For You." Singing to a live audience is still her first love, she readily admits. "I like being onstage, I think that's what this business is really all about, and when I sing I do all the obvious favorites, some tunes from 'Sunset' and 'Blood Brothers' and 'Finian's Rainbow,' a little Elton John, a few of my own songs, anything really." "I don't look for anything though," she says. "Things just come to me -- 'Blood Brothers,' 'Sunset Boulevard,' all of that. Things just happen to me. "If somebody comes along with a wonderful role and it's perhaps off-the-wall for me, I feel I would probably be more able to tackle it now that I've done 'Sunset Boulevard.' I found out some things about myself since I've been doing this that are quite interesting. "I had never been asked before to show such strong emotions before -- hate, envy and desperation. I've never had to dig around inside myself that much before. Now I know I can, and I know it's there. It's quite a release, really."

"SUNSET BOULEVARD"
8 p.m. Friday; 2 and 8 p.m. Saturday; 2 and 7 p.m. Sunday.
Andrew Lloyd Webber musical starring Petula Clark.
$36.50, $39.50, and $42.50. Ongoing from 2/26/99