"I'm so used to having a script," the double-threat says. "The initial idea of writing music was sort of terrifying."

Credit: Michael Tran/WireImage

The actress, 18, got her start in movies like Pitch Perfect 2. But on her debut EP, Haiz, out Nov. 13, she proves she’s a fierce force to be reckoned with. Below, Steinfeld tells EW how she’s gone from Oscar-nominated child star to bona fide pop star.

What made you want to make a transition from movies to music?

With acting, I’ve never given anyone the opportunity to get to know me personally—I choose a character that I love and identify with and I hope that there’s something in there that someone can relate to. But with music, [it’s] putting my own name on my own story.

Are you nervous for the world to hear you sing?

There’s always the moment before you put something out into the world that’s like, “Could this be bad?” But with [my single] “Love Myself,” there was very little question as to whether this should be anything but the first single. I wanted something that had an incredibly strong message and that meant something to me.

On the song “Hell Nos and Headphones,” you sing about feeling like an outsider at a party.

I remember trying to make conversation at a friend’s house once and just getting, “Oh, cool, yeah, great.” And then the turned shoulder. I was standing there like, “I look like a complete loser!” So I faked a phone call in a house where no one gets service and went home. Then I went into the studio in a rage and was telling this whole story about not understanding why I couldn’t get these people to talk to me. It’s amazing how something like that song can come out of one night.

What do you say to naysayers who think actors can’t become musicians?

I’ve never worried that people aren’t going to take me seriously. There was some concern on both sides about what my main focus would be. For a second, I felt like I had to [pick] one over the other. But it didn’t take long before I realized it was very easy to say, “Both.”

You’re part of Taylor Swift’s “squad” and appeared in her “Bad Blood” video. What has she taught you about becoming a pop star?

I’ve learned so much in the last couple years of my life. And I owe a lot to my friends that I’ve met through the business—and friends that I’ve known since I was younger. But I think growing up in a world where it’s so hard to be understood and heard in the right way, I’ve learned the importance of having self-love and self-confidence.

This story originally appeared in Entertainment Weekly issue #1389, on-stands date Nov. 13, 2015.