Behind-the-scenes footage of Billie Eilish and Finneas in the studio reveals the moment they overcame writer’s block and hit upon the idea for What Was I Made For?

There are plenty of reasons why you might want to record your songwriting and production sessions. Following a spate of plagiarism accusations, Ed Sheeran says he now does it in case he ever needs to provide evidence of his originality in court, but even if your music is unlikely to ever trouble the chart statisticians, capturing your process on camera can still be instructive, and will ensure that a good idea is never lost.

It now transpires that Billie Eilish and her brother Finneas are among those who record their time in the studio: “We thought it would be an interesting experiment,” Finneas recently told Jimmy Kimmel, adding that they’re currently capturing the making of a new album so that the footage can be used in an upcoming documentary.

We don’t have to wait for that, though, because Eilish and Finneas were happy to show Kimmel and his viewers a short clip that was recorded as the pair were in the process of writing What Was I Made For?, their hit record from the Barbie movie soundtrack.

Here, we see the moment that Eilish hit upon the “made for” lyric, which turned out to be the cornerstone of the entire song. It was a particularly fortuitous moment because, prior to that, progress had been slow.

“It was this random day in January and we had, like… honestly, I’d been there for like six hours and we were just very uninspired and being just so unproductive,” says Eilish. “And I probably had my keys in my hand and was walking out the door like, ‘OK, this day is trash’, and Finneas was like ‘should we just try to write this one?’ And I sat back down and he started playing those chords immediately, and then together we wrote [recites lyrics to What Was I Made For?] And as soon as we wrote that and then we finished it with the ‘what was I made for?’, I think think that full sentence was just like, ‘OK, we’re doing this?’”

It wasn’t all smooth sailing from there, though: Eilish and Finneas also told Kimmel that they ended up getting rid of a “terrible verse” in the song after agreeing that it didn’t work. EIlish also admitted that Bad Guy, her breakout hit, “is like the stupidest song in the world,” adding that “I'm trolling you, you know what I’m saying? That song is supposed to be goofy but it’s just funny. I’m like ‘it’s dumb!’”

Overall, though, the pair say that they like what they create, with Eilish admitting that it frustrates her when she hears an artist being “hateful” towards their own music. “I’m like, why are you doing this then?’” she says.