Sir Rod Stewart and Jools Holland stunned commuters by putting on a rollicking live show at London St Pancras station last month. Stewart was in blistering form at the pop-up gig, entertaining fans with an energetic performance and a husky vocal on the showtune “Almost Like Being in Love”. The frontman is known as more of a rocker but clearly he can swing with the best of them as well.

Holland held down a lively rhythm on the piano as he led a full big band through the arrangement. The commuters were just lapping it up as they absolutely packed the departures hall, with big smiles all around. Check out the surprise performance for yourself below.

Stewart celebrated his 79th birthday shortly after the performance, but you wouldn’t know it from the clip, as he was dancing around the hall like a fresh-faced kid. He had two beautiful backup vocalists to keep up with so maybe that gave him some extra motivation.

The two English stars dropped in to make the performance to promote their new album, Swing Fever, which was a collaborative effort. The album is due out on February 23 and features 13 tracks inspired by the heyday of big band music in the first half of the 20th century. Stewart has surprised fans with street performances before, as he’s also been captured sitting in with a busker on “Handbags And Gladrags” at Piccadilly Circus.

Stewart told Rolling Stone that he’d always be a rock star, but that he was loving working in jazz. “I just love singing these songs,” he said. “It’s like heaven for me to sing these songs. It really is heaven. I think as well, I think that the truth of it is, you know, I came out of rock and pop groups and that’s why the swing part of me has only come out now.”

The rocker will take the show on the road next month, starting with a US tour, followed by legs in Asia, Europe and a Las Vegas residency.