Ian McKellen leads musical tribute to Patrick Stewart at fundraising gala

Ian McKellen led an on-stage musical tribute to his late friend Patrick Stewart at a fundraiser on Sunday.

The Lord of the Rings actor was a surprise guest at the Raise the Roof! fundraiser at London's Victoria Palace Theatre on Sunday.

Telling surprised theatregoers that he wasn't going to use a microphone, McKellen recalled working with Stewart on the stage play Waiting for Godot and singing the song Underneath the Arches.

"When we played the tramps in Samuel Beckett's Waiting for Godot, Pat Stewart and I sang that song - here in London and on Broadway - at the end of the show," he said, according to footage posted on social media. "And we're going to sing it now for you; I hope you join in. Now I've reminded you of some of the words."

He added, "As we sing it, let's remember Pat Stewart, a great actor."

McKellen then sang a rendition of the song with a bunch of performers, including the fundraiser's host and TV presenter Bradley Walsh.

The show helped raise funds for Denville Hall, a retirement home for those in the performing arts.

Stewart passed away at his home in Los Angeles on 28 October at the age of 86 following a battle with Alzheimer's disease and Lewy body dementia.

McKellen, who had been good friends with Stewart for 50 years, paid tribute to the Star Trek legend on social media at the time.

"Before everything else, Patrick was defined by being born and bred in Yorkshire, the proud county in the north of England which he loved to the end. You could hear it in his accented voice and in the stern honesty with which he told you what he thought and felt," he wrote. "Yorkshiremen have no truck with half-truths or avoidance of big issues. He wore his heart on his sleeve, which made him a man to rely on, to admire and in my case, love."

McKellen, 87, and Stewart starred in Waiting for Godot in London in 2009 before reprising their roles on Broadway in 2013.

They also starred as Magneto and Professor X in the original X-Men franchise. They will appear on-screen together one final time in Avengers: Doomsday, which opens on 18 December.