I heard this song on my way from Napa to SF today and loved it! Took me a while to find it since all I could remember was “lion”. FOUND it and it’s on YouTube! More info on Mumford and Sons is here.

(You’ll see a message saying “Watch on YouTube”. Hopefully if you click on it you’ll be connected to the YouTube video).
WARNING: Cover your sensitive ears as this is not the “clean” version they play on the radio. Sorry about that.