Hundreds of fans lined up Wednesday morning outside Barrelhouse Ballroom in Chattanooga, hoping to get tickets to a surprise pop-up concert for Phoebe Bridgers. The venue posted a sign on its building Wednesday saying Bridgers would be performing there that night, and the box office opened at noon for first-come, first-serve tickets that quickly sold out.

By 6 p.m., doors were set to open for the concert, turning an ordinary Wednesday into a scramble for seats as word spread through the crowd. Bridgers, 23, has built a following with her melancholic indie-folk and rock sound and her witty, introspective lyrics, rising to prominence with the solo albums Stranger in the Alps and Punisher.

She has also become known as part of Boygenius, alongside Julien Baker and Lucy Dacus, and as a member of Better Oblivion Community Center. That wider profile helps explain why so many fans showed up before sunrise, and why the tickets disappeared almost as soon as they went on sale.

For Chattanooga, the surprise show was a one-night test of how fast a quiet announcement can turn into a citywide rush. For fans, it ended the way these moments often do: with a line, a sold-out box office and a night they will remember because they were there when the sign went up.