Muse sings about relationships on The 2nd Law. The group are known for basing their records on grand concepts - including capitalism and megalomania - but have largely kept their relationships out of their work until now.

Singer Matt Bellamy - who became a father for the first time during the recording of the album - said, "We're singing about things like relationships for the first time. Actually, I did that for a bit on the first album, Showbiz, but then I started doing interviews and thought, 'Oh my God, I can't answer these questions, they're getting too personal.' So that's when we started getting all conceptual and pretending the album was about the end of the world, or whatever,"

The singer - who is dating Hollywood star Kate Hudson, with whom he has 14 month old son Bingham - explained how the band's new single, "Madness," is about a couple arguing: "Madness is about friction in a relationship, resolving conflict with a loved one and the madness of being caught up in fighting with someone you love."

Also on the album, two tracks have been written by bass player Chris Wolstenholme, about his battle with alcohol, which he has since beaten and is now sober. "Both of those lyrics were written at that time when I'd stopped drinking. 'Liquid State' was written about the person you become when you're intoxicated. 'Save Me' was about having the family, the wife and kids and, despite all that crap that I've put them through, they're still there and they're the ones who pulled you through," he said.