Billie Eilish plays secret acoustic show at Nashville's Third Man Records

Dave Paulson | The Tennessean

In 2020, 17-year-old Billie Eilish will embark on a massive world tour. It's already sold out. 500,000 tickets were purchased in the first hour, according to her agents.

On Wednesday, the pop sensation was playing for an audience in Nashville that couldn't have numbered more than 200.

Eilish and Finneas O'Connell, her brother and collaborator, took the stage at Jack White's Third Man Records to cut a live album, direct-to-acetate disc. The crowd at the secret, invite-only show was a mix of hardcore fans and industry members.

"Do you see that?" Eilish said, pointing to the live video feed of the recording process. "They're like making my voice onto a thing. Like right now! That's crazy."

Even though Eilish's debut was released this year, a live album can't come soon enough.

Despite everything you'd assume about a pop superstar, there's no team of producers and writers shaping her sound. It's all crafted by her and O'Connell.

And while they've successfully translated their bass-heavy studio sound to arenas and festivals, their songs — and her voice — really shine in a live acoustic setting.

That was definitely the case at Wednesday's show, as neither sibling hit a sour note through 11 songs — though Eilish laughed as she stumbled over a few words of her biggest hit, "Bad Guy."

Among the acoustic highlights were "Ocean Eyes" (one of her first songs, recorded when she was 14), "Bury a Friend" and "I Love You."

Eilish seemed nervous about the length of the latter song, even suggesting the crowd sit on the floor for it, but it earned the biggest applause of the night.

She was introduced by White, who said the singer was "someone we really love, and we think is really innovative and inspiring."

Before playing the set-closing "When The Party's Over," Eilish thanked White for hosting them and "inspiring a whole generation of people to do what they want."

"All I ask is we all try to be just happy we're alive, and happy that we're breathing. That we're here and we're safe. That's pretty much it, for us to all be grateful that we're here right now."

The vinyl edition of Eilish's live album will be available in December only at Third Man retail locations in Nashville and Detroit.

Eilish will return to Nashville to perform at Bridgestone Arena on March 27, 2020. The concert is sold out.

Billie Eilish setlist at Third Man Records in Nashville

Wish You Were Gay (Not recorded)

All The Good Girls Go To Hell

Ocean Eyes

Bad Guy

idontwannabeyouanymore

Bury a Friend

Come Out And Play

Copycat

I Love You

Bellyache

When The Party's Over