Before Billie Eilish embarks on a massive world tour in 2020, the 17-year-old has recorded an intimate acoustic live show in Nashville on Wednesday. The secret invite-only concert didn't take place in any recording studio, however. The singer and her brother Finneas O'Connell played a 11-song acoustic set at Jack White's Third Man Records to cut a live album, direct-to-acetate disc.

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Born Rotten

A post shared by FINNEAS (@finneas) on Nov 6, 2019 at 8:24pm PST

As The Tennessean reports, the crowd was made up of hardcore fans and industry members and "couldn't have numbered more than 200". The set included songs like 'Ocean Eyes', 'Bury A Friend', 'Bad Guy' and 'I Love You'.

Apparently, Eilish was fascinated by the technology with which the concert was recorded, saying, "Do you see that?They're like making my voice onto a thing. Like right now! That's crazy."

Naturally, Jack White also made an appearance, introducing the singer as "someone we really love, and we think is really innovative and inspiring."

Eilish later returned the favour, thanking White for "inspiring a whole generation of people to do what they want."

According to The Tennessean, the vinyl edition of the live album is set to be released in December but will only be available at Third Man retail locations in Nashville and Detroit.

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Thank you @billieeilish and @finneas for the amazing intimate show in the Blue Room tonight. Fans, this was recorded direct-to-acetate and will be available on LP via #ThirdManRecords retail locations only (Nashville and Detroit) next month. Stay tuned... #billieeilish

A post shared by Third Man Records (@thirdmanrecords) on Nov 7, 2019 at 4:28am PST