Taylor Swift made a surprise appearance during the 1975’s concert at the O2 Arena in London tonight (January 12). Swift brought her acoustic guitar onstage for a debut performance of her Midnights track “Anti-Hero.” She also covered “The City,” which appears on the 1975’s 2013 self-titled LP. Fans have posted several clips of her appearance on social media.

In March, Swift will kick off her own tour, which winds across North America through August 9. Scores of fans had issues securing tickets for the trek when Ticketmaster bungled the public on-sale date for the Eras Tour in November. Multiple fans affected by Ticketmaster’s mishandling of the situation have banded together, filing two lawsuits against the ticketing giant and its parent company Live Nation.

Read “6 Takeaways From Taylor Swift’s New Album Midnights” over on the Pitch.