Out of the aggressive music and violent lyrics of Thrash/Speed Metal acts like Slayer rose Death Metal, a dark specter that played faster, with ultraviolent subject matter. In the '80s, bands from the U.K. - Napalm Death and Carcass - and from Florida - Obituary and Morbid Angel - created sounds appropriate for snuff films. Wallowing in gore, these bands used hyperbolically violent lyrics. Death Metal is a low-rumbling beast, using down-tuned guitars to emphasize the bass, while the vocals rant ghastly tales in a deep, throaty, often incomprehensible Cookie Monster growl. Speedy blast beats move the sound at a velocity that challenges the threshold of human ability exemplified by technical masters like Napalm Death drummer Mick Harris -- as much an athlete as a musician -- and the low, rhythmic blur of bands such as Gorefest. Though Death Metal is largely unevolved, its more political and punk elements spawned Grindcore. In Scandinavia, Death Metal bands became more gothic in tone, addressing Satanism, paganism, and Viking lore, and eventually mutating into Black Metal.