Actually the origins of death metal are quite different from what it is today. Death was the first band to be remotely close to death metal. What death metal is today is different from Death, but none the less they paved the way. Morbid Angel came along soon after and gave death metal a lot of signature qualities (like the vocal style, deep guitars, things like that) which have since been branched off of. Cannibal Corpse... well... they were at the dawn, but that's about it. I guess for their time they took the violence thing to an extreme. Possessed was the band to coin the term "death metal". Just a tidbit of info for kicks.