After slithering her slinky self through countless music videos, pop siren Christina Aguilera will sizzle on movie screens for the first time in Columbia Pictures’ song-filled drama “Burlesque.”

“It’s sexy, it’s sensual,” she promises. “The whole idea of burlesque has always intrigued me. The art of the tease, the dance, beautiful women — need I say more?”

Aguilera plays Ali, a plucky girl from Iowa who runs off to the big city to follow her dreams and lands a job at a struggling nightclub. Yet it was her character’s heart and grit that caught her eye. Says Aguilera, who has been candid about her own childhood travails: “It wasn’t just a girl who comes to L.A. and makes it big. It was a girl who had suffered and felt pain, been in seven foster homes. She doesn’t let her past make her a victim. And that to me was so appealing. I could relate to Ali as a whole: having this dream, being denied, getting a chance, and getting people to take you seriously, because it took a few times before someone bit and I got my big break,” she says.

“Burlesque” director/writer Steve Antin had long been friends with Aguilera, but what cinched it for him was her appearance on “Saturday Night Live,” which made him certain that she had the chops to portray Ali. “I had this instinct about her,” Antin notes. “I don’t think people realize how tough it is to be funny in a live element like that. I knew she could do this based on her instincts in those seemingly simple, but really incredibly difficult comedy skits. I knew she could do any of the comedy in the movie and all of the drama.”

Antin was also impressed by how quickly Aguilera adapted to a new type of performing. “She figured out how it works within weeks. She is a little bit of a freak of nature and a perfectionist. This girl is a movie star.”

The novice actress found the perfect mentors in such castmate Cher, who hasn’t had a major film role since 1999’s “Tea With Mussolini.” “I love no-bull-(expletive) women, and she’s the best of the best,”

Aguilera says of Cher, who plays Tess, owner of The Burlesque Lounge. “An original trendsetter in her time and a legend in mine. I found her kind and warm. She had helpful advice and stories for days.”

Aguilera did more than just act, sing and dance in “Burlesque” — she also co-wrote three of the songs that appear in the film: “E.X.P.R.E.S.S.,” “Bound to You,” and “Show Me How You Burlesque.” She offered to write the music and Antin graciously accepted. With a caveat, though. “Christina said, ‘Does that mean if I write one and you don’t like it, it’s not in the movie?’ And I said, ‘Yeah,’” Antin jokes. “That’s basically it. She’s not afraid of a challenge, a girl like Christina Aguilera. She went out and wrote song after song after song, and it was spectacular. We talked a lot about what those songs were. I wrote treatments for the songs, about what story those songs tell in the movie and what the subject matter is, and what the tone of the songs might be.” Antin did write one of the key songs that Christina performs in the film – “But I’m a Good Girl.”

Aguilera says she and Antin bonded from day one on the movie. “There’s something about him that I felt I’d known my whole life,” she reveals. “He was involved with every aspect, and he cared about it like it was his baby. It makes you not want to disappoint him even more. He was great.”

All in all, Aguilera says audiences for “Burlesque” can expect a fun song-and-dance ride from beginning to end. She adds: “It was a really beautiful thing to be a part of, and I think it shows onscreen. Audiences will see how much heart we put into this picture.”

Opening soon across the Philippines, “Burlesque” is distributed by Columbia Pictures, local office of Sony Pictures Releasing International.