Roger Daltrey had not planned to perform with the Foo Fighters at Britain's NME Awards on Wednesday night (23Feb11) - revealing the rock collaboration happened "on the spot".
The Who legend appeared on stage with frontman Dave Grohl as he presented him with the Godlike Genius Award at the London ceremony.
Daltrey then shocked fans by joining in with the band's live performance, taking to the mic for The Who's track Young Man Blues, which the Foo Fighters often perform on tour.
But now the rocker has admitted he only agreed to sing with the band at the very last minute.
Daltrey explains, "They play it in their show sometimes, Young Man Blues, and (Grohl) said, 'Would you sing it?' That's what rock 'n' roll used to be like, when people used to just get up and make it up on the spot. Which is what we did tonight - I hope we didn't show up too much!"