When Christina Aguilera enlisted Ladytron to write songs for her upcoming fourth album, 'Light & Darkness,' she could have wielded her diva powers and told the British electro-pop group exactly what she was looking for. Thankfully, that's not what happened. "She just told us she wanted to enter our world," Ladytron multi-instrumentalist Reuben Wu tells Spinner. "She didn't want to give us any idea what she wanted the music to be. She wanted us to do our own thing."

Wu says Aguilera approached the group two years ago and that the surprisingly modest pop star wasn't shy about declaring herself a fan. "She said she was inspired by our music and we were one of her favorite bands," he says. Although Wu and his cohorts -- fellow keyboardist Daniel Hunt and vocalists Helen Marnie and Mira Aroyo -- were initially required to remain hush-hush about the project, they couldn't keep their secret from everyone.

"What do we do but tell our parents?" Wu says. "Christina is one of those people where you know your parents would have heard of her, so it's kind of good for us to tell our moms and dads, 'Look, mom, look, dad -- we're actually doing something you can understand.'"

Over the course of 10 years and four studio albums, Ladytron has earned praise from and toured with the likes of Nine Inch Nails and Depeche Mode, but the Aguilera collaboration marks the first time the Liverpool quartet has written for another artist. "Working with Christina was a completely different experience," Wu says. "To hear her singing on those tracks, it was pretty shocking how great her voice is. Obviously, you hear it on MTV and on the radio, but to actually listen in front of you, singing in front of you, it's a completely different thing. And quite a few of the songs, she just did one take, and that was it."

Due out early next year, 'Light & Darkness' will also feature contributions from Goldfrapp and Sia Furler -- electronic artists whose involvement suggests Aguilera is trading the retro-pop vibe of her last album for something more futuristic. "My feeling is that she got to a point in her life where she wanted to take her music to a different level," Wu says. "She was willing to take a risk and go in a completely different direction. It wasn't like, 'Oh, I want to be all electro.' It wasn't anything like that. She just wanted to evolve her music according to what she was listening to at the time."

Besides Ladytron, Aguilera has evidently been getting down to Brazilian dance rock and '90s British punk. While visiting the singer in Los Angeles recently, the members of Ladytron rode with her to a CSS show, blasting Elastica jams in the back of her limo. "She's got really good taste," Wu says.

Wu isn't sure how many of Ladytron's tracks will make the finished 'Light & Darkness,' but he says all of the songs pick up where the group's last album, 2008's 'Velocifero,' left off. In working with Aguilera, Wu and company were even inspired to write some major-key tunes, something the darkly dressed, quasi-Goth party starters aren't exactly known for.

"I'm glad to say they're still very Ladytron, and they're also very Christina, because her voice is on the tracks," he says. "We're very pleased with it."