IT'S A SCHOOL NIGHT, and Clementine Creevy is doing interviews.

She's in her room, transferring contacts to her new iPhone, and when she answers my call she seems to have all the time in the world. Evenings like these, though, are quickly coming to an end.

"Six weeks," Creevy says. Six weeks until she's free.

Creevy is 18, a high school senior. She fronts Cherry Glazerr, a spry, barebones three-piece with classmate Hannah Uribe on drums and boyfriend Sean Redman on bass. They have a record, Haxel Princess, on the burgeoning Burger Records label and a lucrative partnership with Paris fashion house Saint Laurent.

For the moment, Creevy looks forward to a more immediate escape: spring break. It allows the band to leave Los Angeles on a quick West Coast tour. "We can only go on tour for a week at a time," Creevy says. "It just becomes too much work to have to do ahead of time or after we get back—because there's no way to do homework on the road.

"I've tried," she says, laughing. "It's not fun."

Creevy adds, "My school is very supportive. Two teachers in particular, Cassie and Deb. We call our teachers by their first names. We're a progressive school. Hippie-dippy. Well, hippie-dippy, but not easy." Creevy's parents are much the same. Just so long as she graduates, she says, they're happy.

"My parents are both writers," Creevy says. "My mom is a novelist and my dad is a writer and producer for TV."

Growing up in a household at the nexus of art and commerce may well explain Creevy's preternatural ease navigating a world that's salivating for her talents. She answers my questions with a prowess, poise, and charm rarely seen in artists and entertainers twice her age—or, really, any age.

Creevy began playing guitar around age 12 and writing songs not long after. Under the name Clembutt, she put up a few on Bandcamp that found their way to Joel Jerome, a rising musical fixture in LA who runs in concentric circles with Burger Records and has produced other acts like La Sera and Tashaki Miyaki. Creevy considers Jerome a sort of consigliere. With Jerome, she re-recorded the demos she'd originally done in GarageBand. The souped-up versions made their way to another teenage wunderkind, editor and actress Tavi Gevinson.

"Tavi connected with me and was like, 'Hey, I heard your stuff. Would you ever want to submit a song for the monthly theme song for Rookie?' I was like, 'Hell yeah! Rookie's awesome! You're awesome!' So I wrote 'Teenage Girl' with Rookie in mind."

"Teenage Girl" is a looping, shambolic, hooky, cooing garage-pop chanson. Its quaintness is feigned, wise beyond the wink of its imagery. Other Cherry Glazerr tracks like "Grilled Cheese" and "Bloody Bandaid" are equally enchanting.

But Creevy's compositions are catching more than just teenage hearts—they've caught the attention of grown critics like the New York Times' Ben Ratliff and Jon Pareles, who discussed Creevy on that paper's pop music podcast last year.

"Clementine has serious songwriting talent," Pareles said. "She has also got stage presence, and that's a rare thing still."

"It's a lot to have for 17," added Ratliff at the time. "Which is why, I guess, it's unclear whether their next album will be on Burger Records."

But whatever Creevy knows about that, she still isn't telling. "Oh man," she says, "I want to say so much stuff that I can't say yet."

She does admit, though, that the offers have been rolling in and that they go beyond music and modeling. Recently, she turned down a lead role in a small horror film. The modeling gigs, though, she's happy to have.

"They treat you like a princess for four hours then you go home and get a fat paycheck," Creevy says. "It's pretty cool. I did say: If they ever tell me to lose weight I'm out of the game. That's it, I'm done.

"It can be detrimental to young girls," she adds. "It's weird being a feminist and a model. That is something that I have to grapple with... I'm trying to learn how to pick and choose the right stuff."

Making music, Creevy says, will remain paramount. And graduating high school will bring with it bigger and more varied opportunities, beyond merely the chance to finally tour Europe.

"I am just sort of sick of people pegging us as a teenage band, or a female teenage band," says Creevy. "It almost makes me kind of upset because I don't want expectations to be lowered for us."