Mumford & Sons have not released a new album in three years, but that's all about to change with Delta, the group's fourth full-length studio project, which is scheduled to drop on Nov. 16. However, in the meantime, fans can hear "Guiding Light," the first single off of the upcoming record on the radio and streaming services.

Recently, The Boot caught up with banjo player and Mumford & Sons member Winston Marshall to chat about the new song, which he says was the product of both careful, exacting work and lightning bolt-style inspiration. Read on to learn the story behind "Guiding Light." 

This was a song that had very many incarnations.

I remember coming in one morning, and Marcus had been up late in the studio, and he had that chorus. He also had completely different verses. I think those [original] verses might have ended up in a different song.

But I just remember going, "That's it!" and pointing at the speakers. I said, "Yup, that's it, that's the one." For me, it was very immediate.

And that happened several times, to be honest. We had pretty good luck in the band, in terms of writing and all that. We feel very privileged in that respect, and it's always exciting when you see the magic happen.

So, that happened, and then we took the song to Paul [Epworth, our producer] in the studio in North London, and we spent a long process of trying to work out which verses were what, what melody was it, and the arrangement. It was a lot of choosing in that song.