Mumford break America? Er, not quite – but we can dream.

The fire-n-brimstone folk-rockers did at least blag a slot on David Letterman’s talk show, a right of passage for any up-and-coming band – and they killed it, even if frontman Marcus Mumford did have to change ‘fucked it up’ to ‘messed it up’ to avoid an international diplomatic incident.

http://www.youtube.com/watch?v=REPctGLpWqk