Grindcore is what you get if you fuse hardcore punk with heavy metal then throw in slabs of industrial noise. The sound, pioneered by Napalm Death, is unrelenting and heavily distorted. While some songs address similar social concerns to those common in hardcore, grindcore can also embrace themes of violence/horror. Not surprisingly, given the themes, vocals are usually extreme, either screaming or guttural growling. The percussive 'blast beat' is a common feature, a fusillade of rapid attacks on various parts of the drum kit that is like an explosion of sonic violence.