Taylor Swift made a surprise appearance — and gave an impromptu performance — during the kickoff of Tight End University in Nashville on Monday night (June 24), delivering an acoustic version of her 2014 smash hit “Shake It Off” to a room full of stunned NFL players and guests.

The pop superstar joined boyfriend Travis Kelce at the annual three-day training summit, which he co-founded with NFL peers George Kittle and Greg Olsen in 2021. The event, held at Vanderbilt University, was originally designed for tight ends across the league to train, network, and share techniques, but this year, it also doubled as a moment of Swiftie history.

In a fan-recorded video that quickly went viral on X (formerly Twitter), Swift is seen onstage at the event’s opening night afterparty, performing her Billboard No. 1 hit “Shake It Off” live with her acoustic guitar. Dressed in a short black dress and heels, she strums and sings to a crowd that erupts in cheers as Kelce watches on from backstage during the performance. Watch it here.

Swift’s appearance wasn’t officially announced, making the moment even more memorable for TEU attendees. According to DJ Mike Fresh, who helmed the night’s music, the energy shifted when Swift entered the building. “There are Monday fun days, and then there are Monday fun days when Taylor Swift is in the building partying to your set,” he wrote on Instagram.

While Swift has wrapped her Eras Tour, the Nashville appearance marked one of her first semi-public performances since finishing the historic run. Tight End University marked another crossover in Swift’s increasingly visible support of Kelce’s career, from celebrating his Super Bowl win to attending multiple Chiefs games during the NFL season.

The couple also made waves at the kickoff event for another reason: it marked their first official “red carpet” moment together. The duo walked into the venue hand in hand, smiling for the cameras — Swift in her green-and-white checkered ensemble, which sold out online in just hours, and Kelce in a coordinating white-and-yellow outfit.

But for many fans, the real highlight was the stripped-back, joyful “Shake It Off” performance — a reminder that Swift can command any room, football-themed or not.