Last night, Wednesday, Oct. 26., Taylor Swift made a surprise appearance during Bon Iver’s performance at the OVO Arena in Wembly in London. Swift and Bon Iver’s Justin Vernon collaborated on Swift’s beloved song “Exile” off her eighth album folklore, and as he began the first few verses of the song, Swift appeared on stage.

The appearance of Swift came after Vernon’s Big Red Machine collaborator The National’s Aaron Dessner performed their song “Reese,” and Dessner stayed on stage for the live debut and duet of “Exile.” According to the Independent, while she was sharing the stage with Vernon and Dressner, she called them “the most talented men in the world,” and after she left the stage, Vernon joked to the crowd saying it would be a hard act to follow before playing fan favorites “Skinny Love,” “Blood Bank,” “33 “GOD”,” “Holocene” and “The Wolves (Act I and II).

Swift’s appearance came incredibly hot on the heels of her newest album, Midnights, which was released on Oct. 21 and crashed Spotify. The LP currently holds the record for the most-streamed project in a single day in the service’s history.

Upon Spotify sharing her record-shattering statistic, Swift tweeted: “How did I get this lucky, having you guys out here doing something this mind-blowing?! Like what even just happened??!?!”

The release of Midnights also marked the second time ever that a musician’s LP reached 1 million sales in its opening week, a milestone that Swift and only Swift has achieved since the release of her 2017 album Reputation. 

As for Vernon, he’s further pioneering upgraded avenues for sonic experiences by partnering with the French company  L-Acoustics for select immersive sound shows equipt with their  L–ISA technology, which was featured during last night’s performance.

Watch a video of Swift joining Bon Iver below.