Roger Daltrey squeezed in a warm-up gig before taking the stage in Glasgow with the Who on their 50th anniversary tour -- but not with Pete Townshend. Instead, Daltrey sat in with a stunned wedding band, after stumbling upon the nuptials of Susan and Carl Smith at the Mar Hall resort, where he was staying in Bishopton, Scotland.

"Basically we were coming towards the end of our set and we were sort of halfway through a song," Graeme Allan, lead guitarist for Milestone, told BBC Radio. "I remember looking over to the side of the dance floor and a wedding guest was actually walking with Roger, coming towards the band."

Daltrey proceeded to congratulate both bride and groom, mentioning Carl Smith's service in a parachute regiment -- then Daltrey and Milestone launched into a pretty credible version of the Who's 'I Can't Explain,' as seen in the above video.

“I think one of the main reasons he came in is that he wanted to thank all of those guys for their service," Susan Smith said later. "Afterwards, we had a little chat and he was congratulating us and wished us health and happiness for the future. He was really sweet."

The Who Hits 50 tour continues in the UK through December, then heads to North America in April. A dollar from each ticket sold will benefit Teen Cancer America.

See the Yearbook Photos of the Who's Keith Moon and Other Rock Stars

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