Mumford & Sons are Back With a New Single “Guiding Light” It has been a long three years since Mumford & Sons released their last album; the world feels like a completely different and unrecognizable place– a place that needs Mumford & Sons’ monumental unifying music more now than ever. “Guiding Light” is simply put, our guiding light. It’s a driving force of a song that holds our hand and propels us forward to a new, but familiar place– a place where the echo of the audience singing Marcus Mumford’s lyrics back to him will travel for miles.