Charlotte Aitchison, the pop singer who performs as Charli XCX, has a runaway hit on her hands, though you wouldn't know it.

Well, you'd know Icona Pop's "I Love It" if you heard it on the radio. Or as the theme song to MTV's Jersey Shore spinoff Snooki & JWoww. Or the episode of Girls where Hannah does coke for the first time. Or, as I did the other day, out of the mouths of a gaggle of third-graders just leaving school.

Although the public face of the song is the two lanky Swedes who make up Icona Pop, it was Aitchison who provided the real heart of the song, writing its lyrics and melody, as well as providing backing vocals.

"It's definitely weird hearing it on the radio and hearing my voice all over it and no one thinks it's me," says Aitchison, taking a break from preparation for her U.S. tour. "That song's done so much for me, though. It's opened so many doors, and people are considering me as a serious songwriter now. And it's paying my bills, which is cool."

"I Love It" is also helping to nudge open the door for Aitchison's own music. True Romance, the album she released earlier this year, is a marvel of modern pop sensibilities, a mélange of blood-pumping electro, ghostly R&B and tracks that sound like showers of glitter, all wrapped in a pair of torn black stockings.

As complete and timely as the album feels, some of the songs have been around for five years, written when the 21-year-old Aitchison was 16.

"The record sounds like a diary to me," she says, "like a journey of me discovering who I am, coming of age as I'm traveling around, doing sessions in L.A. and Stockholm."

Now that she has those songs behind her, Aitchison wants to move forward. She is working on a new album to be released next year, and has already unleashed its lead single, an ecstatic '80s-style anthem called "SuperLove."

"That's just a taste," she says. "The rest of the record is very influenced by '60s French pop, like Serge Gainsbourg and France Gall, and then '80s stuff like Bow Wow Wow and the Waitresses. It goes into a lot of weirder places."

Like True Romance and unlike "I Love It," the new album might be strange enough to make it difficult to crack the charts in the U.S. and her native U.K. But, as she says, work like hers and that of her peers—Robyn and Grimes, to name two—is all part of the pop-music long game.

"I feel like what we're doing is so freaking important to mainstream pop," Aitchison says. "Even if they're not breaking through or whatever, those artists are so important for pop music to survive, and those sounds will filter through. That's where people will draw their inspiration from."

SEE IT: Charli XCX plays Star Theater, 13 NW 6th Ave., with Kitten & Liz, on Tuesday, Oct. 29. 9 pm. $10. 21+.