Check out this video of Taylor Swift, Ed Sheeran and model Cara Delevingne rehearsing for an impromptu performance at the US ambassador's home in London last night.

The trio can be seen singing the first verse of The Knife's hit Heartbeats at the bottom of a staircase.

Swift posted the clip to her Instagram account with the caption, "Me, Ed, Cara. Singing songs in the US ambassador's house. What is life."