The Breakdown: Billie Eilish and Finneas on 'Bad Guy'

It took Billie Eilish 34 “Duh”s to craft her hit song, “Bad Guy” — or at least that many takes of the word. And all that repetition paid off: Eilish recently garnered six Grammy nominations, including “Bad Guy” for Record and Song of the Year and When We All Fall Asleep, Where Do We Go? for Album of the Year.

Eilish and her producer-brother, Finneas, shared the process they went through to craft “Bad Guy” at Finneas’ California home and how they ultimately achieved “stupiosity.”

They explained their studio setups in their parents’ houses and how they incorporated patterns to craft the layered, distinctive effects. “One of the reason why we left the humming in the beginning is the way the bass sounds, you could think it’s in a different key. … Finneas would often take it out, but I’d go, ‘No, no, no,’” Eilish says.

They also reveal the reasoning behind the very quirky “Invisalign” intro and explain how Plants Vs. Zombies and Wizards of Waverly Place both figure into the track.

Finneas takes gentle jabs at Billie’s perfectionism when it came to enunciating the lyrics, such as “white shirt,” and how she needed it to be “right” — even when it came to the breaths being “exactly the same.”

“I’m actually so shocked and happy that people like it the way that it is,” Billie admits. “The thing we were most worried about was the chorus, and having it have no hook.”