Coldplay invited Michael J. Fox to join them on stage during their headlining set at Glastonbury Festival in England on Saturday.

To introduce the surprise guest, frontman Chris Martin took to his guitar and sang a little intro that elicited cheers from the crowd. “Here’s another legendary Michael. One who just totally rocks, with his Chuck Berry riff and the way he punched Biff,” he sang, referencing Back to the Future where Fox’s character Marty McFly covered Berry’s “Johnny B. Goode.” (Fox has also performed the song with Coldplay previously).

The actor joined the band on guitar for songs including “Humankind” from 2021’s Music of the Spheres and X&Y hit “Fix You.” Fox, who has been battling Parkinson’s disease since 1991, performed from a wheelchair during the set.

Earlier in the night, the band also brought out surprise guest Little Simz. The rapper joined Coldplay to debut a new, unnamed collaboration, which features the lyrics “and so we pray.” The song also includes a verse from Burna Boy, Variety reports, though he was not present during the set. Palestinian singer Elyanna also joined the band on stage for the unreleased song.

Earlier in the month, Coldplay detailed their 10th studio album, Moon Music, which arrives Oct. 4.  Last week, they released the album’s first single, “Feels Like I’m Falling in Love.”

Moon Music, the follow-up to 2021’s Music of the Spheres, will be crafted utilizing “new sustainability standards” that include manufacturing Moon Music’s vinyl and CDs using eco-friendly practices to reduce its impact on the environment. The group has had a longtime focus on sustainability, having so far produced 59 percent less CO2 emissions on their current tour compared with their previous stadium tour.