Actor Bradley Cooper gave the audience at the U.K.'s Glastonbury Festival on Friday quite the surprise when he mysteriously strolled on stage.
The Philadelphia-born celebrity was there to film scenes for his upcoming film, "A Star is Born," a fourth reboot of the 1937 classic, Billboard reported.
- RELATED STORIES
- WATCH: Ellen DeGeneres interviews new dad Bradley Cooper
- Anthony Bourdain dines on pierogies, Yuengling while filming Pa. episode of 'Parts Unknown'
- Bradley Cooper, Lady Gaga appear in first set photo from 'A Star is Born'
In front of a few cameras, Cooper rocked out on guitar and headbanged in front of festival goers, according to NME. Though, there wasn't any actual music to be enjoyed – the sound on Cooper's instrument was switched off, according to the publication.
The actor took the stage before singer Kris Kristofferson performed his scheduled set at the U.K. festival. Kristofferson starred in the 1976 remake of "A Star is Born" along with Barbra Streisand.
"You guys were awesome, that was great – it's my sheer pleasure to introduce Kris Kristofferson," Cooper said before exiting the stage.
The film, which co-stars Lady Gaga, tells the story of a movie star helping a younger actress aspire to celebrity status while his own takes a turn for the worse.
So what will the Glastonbury scenes be used for, exactly? Fans will have to wait and see.
The Warner Bros. picture, which is also directed by Cooper, will premiere in theaters next year.