Mumford & Sons are surprised their latest album sold so well.

The folk rock band can't believe they broke chart records earlier this year with their second effort 'Babel', which briefly held the crown for highest first week sales of 2012 in the US and was the fastest selling album of the year in the UK.

Frontman Marcus Mumford told MTV News: ''We spend our lives in a constant state of surprise at the moment, definitely. We weren't expecting people to [buy the album], especially people who had heard the songs already.

''You could pretty much listen to the whole album on YouTube, just in a different order to the one we put down. Most of the songs were already online ... because we just liked playing them live.''

The 25-year-old singer - who is married to actress Carey Mulligan, 27 - remains nonchalant about the album's success, insisting fans have always supported albums of different genres.

Marcus added: ''The music industry has to talk about something, and I think they're trying to make something out of nothing.

''People have always been buying albums; people have always been supporting different types of music, sometimes some type of music will become more mainstream than it was a couple of years ago, and that's fine, and then it will go out, you know?''

The rocker thinks music these days is no longer ''groundbreaking'' and his band have simply benefitted from the popularity of live gigs.

He said: ''I don't think there's any major groundbreaking thing going on now. I just think the main thing is that people buy tickets to shows; people love seeing live shows, and that's lucky for us, because that's what we love doing most.''