Billie Eilish Was 'Purely Inspired' to Write 'Barbie' Track 'What Was I Made For?' After Overcoming Self-Doubt

The Grammy winner is also "really proud" of the music video she directed for the song

Barbie came along at the right time for Billie Eilish.

The Grammy winner, 21, was going through a period of self-doubt that went far beyond just writer's block before she and her brother, music producer and songwriter Finneas, came up with their Barbie soundtrack contribution, "What I Was Made For?"

In an interview with Apple Music 1 host Zane Lowe, released on the same day as her self-directed music video for the song, Eilish said the song came about when they were experiencing a "frustration in writing."

"And Finneas has always been the one that's like, 'No, no, no, let's write. Let's write.' And honestly, we were in a period of time where we were both ... like through this last winter, we've both been incredibly uninspired," Eilish explained. "And we've still been working and trying to make stuff. And honestly, that song was the first thing we'd written in a minute."

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About halfway through writing songs during this period, Eilish would think she and her brother "still got it" when they began a track, she told Lowe. Then, the self-doubt would creep in.

"We were really in a zone of feeling like we lost it and feeling like, 'Man, I don't know if we can do this anymore.' And we were like, I was 15 years old, 16, 17, and he's a teenager, you can imagine my thoughts of doubt. Like, 'Oh, I can't do this anymore,' " Eilish explained.

Thankfully for Eilish, Barbie and director Greta Gerwig "just pulled it out of me, I don't know."

Related: Everything to Know About the 'Barbie' Movie Soundtrack

Eilish and Finneas, 25, saw an early cut of Barbie, with just Gerwig and a few producers at Warner Bros, she told Lowe. At the end of the screening, Gerwig asked them to "make something" if they were inspired. Finneas wondered if they should write a "Barbie song," but Eilish rejected that idea. She also realized that writing the track would be different from writing their Oscar-winning title song to No Time to Die. Soon the lyrics to "What I Was Made For?" just "came right out," she said.

"The start of writing this song, the first day of writing, Finneas and I, especially me because it's from my perspective, we were purely only thinking about Barbie," Eilish explained. "I did not think about myself once in the writing process. So that's the full first verse, pre-chorus, chorus, maybe second verse, all in one night."

Eilish said she was "purely inspired" by the movie, its take on Barbie, and how the character would feel. However, she soon realized that the song was really about her.

"I really don't mean this to come off a conceited way at all, but I do this thing where I make stuff that I don't even know is ... like I'm writing for myself and I don't even know it," she said. "It is one of the most incredible things I get to experience in my life. Dude, the next week I was playing it in the car all day and playing it for everybody. And I was like, 'This is exactly how I feel. And I didn't even mean to be saying it.' "

Related: Billie Eilish Transforms into Barbie with a Retro Blonde Hairstyle in the Teaser for Her Soundtrack Song

Eilish called that realization "the trippiest thing" she's ever experienced in her life. "I was like, 'Oh, I absolutely was writing about myself,' but I was thinking about myself from a third person," she said. "And I was thinking about myself objectively, which also made me feel really connected to her, me."

Eilish later said it was "special" to direct the music video for "What I Was Made For?" in which she wears platinum blond hair and a yellow dress as she goes through a box of Barbie doll clothes. "I don't know, I love all my videos, and some of them of course have aged poorly, but I still really love them all," she said. "But this one, I think, I don't know, I feel really proud of it."

Barbie hits theaters on July 21, the same day the soundtrack is released.

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