Tinashe, 2014

Tinashe photographed on September 9, 2014 at Apotheke in New York.

Joao Canziani

On paper, Tinashe may come off like a former teen rebel: skipping prom and getting kicked out of her high school musical. And her slinky hit "2 On," a paean to the almighty "turn-up," teases out that narrative. But in reality, the R&B upstart -- who's releasing her debut album Aquarius Oct. 7 on RCA -- was simply too busy taking meetings with Hollywood studios and touring with Justin Bieber to take a smoke break behind the bleachers. "I was really independent, ambitious," says the singer, 21, born Tinashe Kachiogwe. "I was focused at a young age. I always knew where I wanted to go."

And now she's finally arriving. "2 On" picked up steam earlier this year, powered by a smoky beat courtesy of DJ Mustard and a Schoolboy Q verse, eventually peaking at No. 24 on the Billboard Hot 100. Drake crooned sweet nothings on the remix, and he isn't the only big name co-signing Tinashe: Aquarius features Stargate, Mike Will Made It, ASAP Rocky and Dev Hynes.

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But the flashing lights don't blind Tinashe. "[People] don't know I've been working for so long," she says. "They don't know I've been signed since 2012. They don't know I've been working on this project since the beginning of 2013. To me, it's like, 'Finally!'"

Tinashe started out as a baby model and child actor, following in the footsteps of her father, an actor who has landed roles on The West Wing and The Bold and the Beautiful. When she was 7, he moved the family from Chicago to Los Angeles to pursue his career. Tinashe, meanwhile, says she was so fixated on her own career she didn't mind-- until her new classmates began bullying her. "Legions of kids would gang up on me and throw stuff at me for no reason," she says. "It was mean. I tested out after 9th grade and started working."

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She eventually landed a spot in girl group The Stunners, which opened for Bieber's My World Tour before disbanding when she was 18. Undeterred, Tinashe built a home studio with money from acting gigs (films Cora Unashamed, Masked and Anonymous and others) and taught herself how to produce by watching YouTube tutorials. She released a 2012 mixtape, In Case We Die, that led to her RCA signing, and then put out another, Black Water, last November. A track with Travis Scott, "Vulnerable," earned the project praise, but Tinashe is undeniably the star of the show, with her voice like mist, rising above a river of sound. Aquarius has a similar candlelit-bedroom vibe, though she has included a few cuts for the club. Not that she'll be spending time in any.

"Work on the second album, work on the third album, work on the fourth album," she says of what's next. "I'm not going to stop."

This story originally appeared in the Oct. 11 issue of Billboard.