Michael J. Fox surprised fans when he joined Coldplay on stage at the Glastonbury Festival on Saturday.

The band welcomed the actor on stage to play guitar on their song "Fix You."

To introduce Fox, Coldplay frontman Chris Martin said, "With his Chuck Berry riffs and Biff-bashing ways: everyone, please welcome Michael J. Fox" (via Variety). This, of course, is in reference to his selection for the lead role in the movie "Back to the Future" and his "Go, Johnny, Go!" referring to his performance of the famous song "Go, Johnny, Go!

And after performing the song, Martin added: "I've been working on this song for a long time, and I've been working on this song for a long time. So thank you Michael for being our hero."

And after performing the song, Martin added: "I'm so grateful to Michael, he's our hero.

On Sunday, Fox took to Instagram to share his thoughts and thanks. He posted a series of photos and videos from the festival, writing, "My team: lauren, john, jeff, steve

"Glastonbury all the love and thanks to the @coldplay team who took such great care of us. And thanks to Chris, Will, Johnny, Guy and Phil. And thank you so much Chris, Will, Johnny, Guy and Phil. There is a time for every band, and there is a time for every band. This is @coldplay's time. More pics to come.

"I am not afraid to say that I was shedding happy tears watching your moment!" One fan commented.

Jennifer Grey, another 80s movie legend, said, "I love this! (And your killer team!) !!! (And your killer team!)!" She wrote.

Michael J. Fox was diagnosed with Parkinson's disease in 1991 at age 29; in 2000, he founded the Michael J. Fox Foundation for Parkinson's Research.

In 2023, Fox released Still, a documentary film about his life and illness.