This is one of those songs/performances with a particular nature that gives chills and makes you want to listen to it again and again. If you saw The Hobbit movie (the first of Peter Jackson’s three), then you remember the dwarves singing a rendition of the song. The movie version was different than the version str8voices sings, and for that matter both versions are a bit different from the book’s version.
In the book, The Hobbit, J.R.R. Tolkien wrote, leading up to the song which is much longer than the one in the movie, this:
The dark filled all the room, and the fire died down, and the shadows were lost, and still they played on. And suddenly first one and then another began to sing as they played, deep-throated singing of the dwarves in the deep places of their ancient homes; and this is like a fragment of their song, if it can be like their song without their music.
Far over the misty mountains cold
To dungeons deep and caverns old
We must away ere break of day
To seek the pale enchanted gold. . . .
For the full version see the book and hum the tune as you read!!!