It seems that Blink-182's Mark Hoppus and Mumford & Sons have struck up quite a friendship.

Last week, we brought you footage of the unlikely pairing's cover of Eurythmics' 'Sweet Dreams' - and now they've collaborated again on a live performance of Blink-182's 'What's My Age Again?'

It's difficult to imagine the previous banjo-toting incarnation of Mumford & Sons playing the song, but it seems the foursome are shedding their folky past for a rock future - and they even brought Rage Against the Machine guitarist Tom Morello and producer T-Bone Burnett out to help on the song. Heck, there was even crowdsurfing. Crowdsurfing.  At a Mumford & Sons gig.

Watch the footage of a slightly out-of-tune 'What's My Age Again?', filmed at LA's Troubadour venue, below: