Power Violence is a musical genre combining hardcore punk and grindcore. Characterized by intense speed and radical tempo changes. Blast beats one moment to slow sludgy music the next.
Man is the Bastard officially coined the term Power Violence in their song Hispanic Small Man Power (H.S.M.P)

A loosely defined sub-style of hardcore which almost completely eschews traditional song structure in favor of an all-out blitz-speed musical attack. More well-known power violence bands include Infest, Spazz, and Scholastic Deth.