Powerviolence is an extremely dissonant and fast subgenre of hardcore punk which is closely related to thrashcore and grindcore. In contrast with grindcore, which is a "crossover" idiom containing musical aspects of heavy metal, powerviolence is just an augmentation of the most challenging qualities of hardcore punk. Like its predecessors, it is usually socio-politically charged and iconoclastic.
Powerviolence pioneers Siege performing at their high school in 1984
Thrashcore is a fast-tempo subgenre of hardcore punk that emerged in the early 1980s. Thrashcore is essentially sped-up hardcore, adopting a slightly more extreme style by means of its vocals, dissonance, and occasional use of blast beats. Songs are usually very brief, and thrashcore is in many ways a less dissonant, minimally metallic forerunner of grindcore. The genre is sometimes associated with the skateboarder subculture.
Craig Setari of New York thrashcore band Straight Ahead
Contemporary thrashcore band Trash Talk performing in 2010