Singer Taylor Swift gave a surprise performance for a star-studded crowd at actress Reese Witherspoon's birthday party here over the weekend.
Swift played a mini concert and performed her hit single "Shake it off" with the help from Keith Urban on guitar, reports aceshowbiz.com.
Kate Hudson shared a collage of photographs from the party and a Snapchat video of Swift jamming out with Urban.
The other stars at the soiree included Jennifer Aniston, Justin Theroux, Courteney Cox, Matthew McConaughey, Robert Downey Jr., Nicole Kidman, Tobey Maguire and Jason Bateman.
Witherspoon is turning 40 on March 22. The birthday girl who starred in a 2002 movie "Sweet Home Alabama", at one point hopped on the stage and sang along with the crowd during the party on Saturday night.
