The Lumineers' Jeremiah Fraites was slapped by Elton John, because he didn't believe he could have heard their album.
The 'Ho Hey' band met the legendary singer at the Grammy Awards, but accidentally offended him by not believing he had heard their music.
The band's Wesley Schultz told radio station XFM: ''We saw Elton John's suit and his brightness and his entourage and he turns and Jeremiah says 'I'm sorry man, we're in The Lumineers and we're just big fans of yours.'
''He [exclaims] 'The Lumineers!' and he comes over and our drummer says, 'There is no frigging way you listened to our album' and [Elton] slaps him in the face and says, 'The hell I didn't! I definitely did!'
''He was really upset that we were questioning whether or not he'd heard our album.''
The 'Ho Hey' group - which also includes Neyla Pekarek - have achieved huge success in the last year, but say it has been a long time coming.
Jeremiah explained: ''We've been writing together for seven years, and I think it's been a slow gradual climb. I think we had to make a lot of mistakes with this band before we made stuff that people got into. For about five years of making music it was just not focussed, and through all of the mistakes we made as a band we finally got somewhere pretty neat.''