Mayhem: Deathcrush (1987)
Owing a huge debt to early Bathory albums, the first Mayhem E.P. has gone down in history as being the first commercial release from the Norwegian Black Metal scene. The eerie production makes it sound like hell is opening up in your front room.
It's full of screeching voice, fuzzy guitars, brutal bass and some early Black/Thrash motifs that would be put to better use on their first full studio album. Drums are by Kjetil Manheim, because Hellhammer hadn't yet joined. It's a classic and if you've any interest in the genesis and evolution of the Black Metal genre, then it's definitely worth your time.