Back To The Future star Michael J Fox makes surprise appearance alongside Coldplay at Glastonbury

British rock band Coldplay was joined on stage by actor Michael J Fox for their Glastonbury gig. The 63-year-old actor, who was diagnosed with Parkinson's disease in the early 90s, appeared on stage during the band's outro at Worthy Farm on Jun 29.

Chris Martin, the band's lead singer, introduced Fox as a "legend" before the Hollywood star played the guitar alongside Coldplay and a huge support cast of backing singers.

Martin said: "The main reason why we're in a band is because of watching Back To The Future, so thank you to our hero forever and one of the most amazing people on Earth, Mr Michael J Fox. Thank you so much, Michael."

Fox later took to Instagram to thank Coldplay for taking care of him and called the experience "f***ing mind-blowing."

During the festival, Christ Martin also paid a glowing tribute to festival founder Sir Michael Eavis.

He sang: "To Michael, we just want to thank you. As humans go you're the best of all sorts. You're a musical charmer, you're the world's greatest farmer, who ever got knighted wearing shorts."

Prior to that, Martin hailed the Glastonbury crowd as the most "peace-loving" and "fun-giving" audience.

He told the crowd: "We’re going to show everybody watching on TV why the Glastonbury audience is the most peace-loving, love-making, fun-giving, accepting, non-judgemental, wonderful group of talented, brilliant humans that can sing in tune."

Martin also embraced the experience of performing for such a huge audience.

The award-winning star, who sang many of the band's best-known hits including Yellow and Higher Power, said: "I look around and I just see amazing, wonderful people from all over the place and that’s what makes Glastonbury the greatest city on Earth.

"Thank you, all of you who have been waiting down here at the front for hours. It’s amazing that none of you had to pee.

"And then thank you everybody in the middle of the field for playing that role, we see you. And then at the back of the field, five time zones away, at the back of Glastonbury, maybe the most important engine room in the world.

"We welcome everybody all the way at the back in their Wellington boots. Thank you for all your flags and the singing and everything. This is our favourite thing to do on Earth, so thank you for letting us do it."