This is a song called “Scare Away the Dark” by a folk singer named Passenger (his real name is Michael David Rosenberg and he’s a 30-year old from England). Warning: there’s a tiny bit of nudity towards the end of the video, but it’s done in the name of art.
You can find the lyrics here.
Feeling inspired to go run around outside yet? (I’d suggest keeping your clothes on, though.)