"It was just the way I thought it would be, just the way I pictured it," says Petula Clark in a storybook voice, recalling her first visit to West Virginia earlier this year.

And a good thing it was, too.

Eight years ago, the British pop star, best known for a string of mid-'60s hit songs that included "Downtown," "I Know a Place" and "Don't Sleep in the Subway," began writing songs for a Civil War-era musical based in West Virginia called "Amen."

She found a collaborator in songwriter Dee Shipman, and now, some 20 songs later, the show is ready for production. Or "as ready as these things ever are," asserts Clark, who performs Friday at the Kennedy Center. A well-known director (whose name Clark won't reveal just yet) has accepted the project, and if all goes well the musical will premiere in London's West End next year.

"I knew the story had to be based in West Virginia," says Clark, crediting a rather unlikely source, her friend, "fight doctor" and boxing commentator Ferdie Pacheco, for coming up with the idea of "Amen" in the first place.

To make sure her songs were true to the people and the countryside, Clark and her sister rented a car and drove through the mountains last winter. "We drove through all this snow, sleet and rain, and it was just beautiful," she recalls. "I don't know what it is about that part of the country. I just feel I must have lived there some time before."

Maybe so, but not in this lifetime. Born in Epsom, Surrey, 53 years ago, Clark has spent almost all of her life in the public eye, first as a childhood star, singing for the American and European troops stationed in England during World War II, and later as a film actress and an emerging British pop star. By the time she was 7, her father was already serving as her agent and manager.

A handsome frustrated actor, her father resembled Errol Flynn, says Clark. "He was once bitten by a passion-crazed Errol Flynn fan on the leg. He was very proud of that," she adds fondly, noting that performing in 500 shows for the troops was actually "great fun."

"It wasn't the sort of high-pressure thing that I guess some child stars like Judy Garland went through," she explains. "I loved to sing. I still do. The problems came with adolescence . . . when I started to show a little bosom -- I was very proud of it, actually -- and a certain dress might show it off, we got all these letters, saying, 'My God, what happened to our little girl?' There was this feeling in seeing me grow up they were seeing their youth disappear."

Clark gradually made the transition from film to records in the '50s, but American audiences didn't really take notice of her until she went to France in the early '60s. It was there that she met her husband, Claude Wolff (they have three children), and was introduced to a new song called "Downtown," the first of several hits she would record written by songwriter and producer Tony Hatch.

In some ways Clark's timing couldn't have been better. Her success perfectly coincided with the British rock invasion. Even though she was living in France at the time and not in "with the Carnaby Street crowd," Americans viewed her as part of the excitement the Beatles were stirring up overseas.

But the demands on her time were also extraordinary, creating, in Clark's words, a "wonderful inconvenience . . . I was in Montreal when 'Downtown' became No. 1 in the States and I was so busy with my French engagements, I didn't even have time to go to New York overnight. 'The Ed Sullivan Show' was screaming for me and I told them I just couldn't get the time off. Finally, I arrived late one Sunday for a taping and a dress rehearsal and I had to go straight from my car to the stage. All of a sudden the crowd stood up and cheered. It was my very first experience with an American audience."

Club dates, stints in Las Vegas and even a role in Francis Coppola's screen adaptation of "Finian's Rainbow," playing opposite Fred Astaire, soon followed. ("Dancing with Fred is 10 times easier than dancing with anyone else," Clark says. "He makes you feel like a dancer. I really felt just like Ginger Rogers.") But all the while Clark resisted moving here, preferring family life in Europe.

Now she's on tour again, mixing her own hits with contemporary pop songs from both sides of the Atlantic and tossing in an occasional show tune. She still finds plenty of new songs to her liking, but she's quick to point out that not everything she enjoys suits her voice and style.

"Obviously, I'm not going to do any of Madonna's songs," she says, laughing. "There's a song from 'Fame' I do called 'Out Here on My Own' and I sing it differently than what you hear on the film, because there's not much point in doing it the way someone else has. I think that's what makes it fun -- to take a piece of material that someone else has recorded and in some small way make it your own."