LOS ANGELES (Reuters) – British folk band Mumford & Sons on Sunday said they will release their second album, "Babel," on September 25, calling the eagerly anticipated follow-up to "Sigh No More" a "natural progression" written on the road. "We love playing live, obviously, but it had also become an important part of our creative process. We had been writing and rehearsing in soundchecks, and sort of 'road-testing' new songs on our very gracious audiences. But then we fell in love with recording again," the group said in a statement. …