Creating the theme song for a James Bond movie is a big deal for Billie Eilish.

In a new interview with the BBC, the Grammy-winning star and her brother/producer Finneas talked about the privilege of writing the song for the upcoming “No Time to Die”.

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“It’s a very surreal thing, our lives as a whole,” Eilish said. “But we’re very grateful for it.”

The song, which was released last week, features a soft and slow performance by Eilish, eventually reaching a loud crescendo with classic Bond strings to match.

Finneas also revealed that they recorded the song much like they have their previous hits.

“We wrote and recorded the Bond song on a tour bus in Texas,” Finneas said. “We did certain songs on the album in hotel rooms. You know, that’s kind of always been our philosophy: not letting the place that we are get in the way of making great music.”

In fact, attempting to write the song in a studio turned problematic.

“We had an intense amount of writers’ block as soon as we were called to action,” Eilish admitted.

RELATED: Finneas Reveals He And Billie Eilish Were Given The First 20 Pages Of ‘James Bond’ Script Before Writing The Theme Tune

Despite the writers’ block, Eilish said that she and her brother had wanted the chance to write a Bond theme for years.

“I remember at the beginning of last year we kind of told our whole team, ‘Hey, if any Bond things come up we want to be involved if we can possibly be,’” she said. “‘Whatever we have to do we will do.’”

Finneas added, “We really did not take the opportunity lightly and we really just tried to work as hard as we could to prove ourselves worthy of that. We really wanted to make something that didn’t feel like we were trying to copy other great songs, so it was really helpful to listen to these songs.”

Eilish, at 18, is the youngest artist to record a James Bond theme.