The incorrect term for the under-appreciated genre known as Drone Doom. Quite probably some of the most atmospheric music in metal today, it features minimalistic riffs and sounds to paint a picture in your mind. The lyrics deal with abstract concepts, but usually are melancholic as a whole.
The correct term for drone metal is "drone doom," as our "Deathfuckingmetal" dumbass doesn't seem to know.
Download any Sunn O))) song, it'll make your skin crawl. In the best way possible.