Grindcore is a subgenre of heavy metal music that combines elements of hardcore punk and extreme metal. It is characterized by its fast tempos, aggressive guitar riffs, and intense drumming, often featuring blast beats. The lyrics typically address social and political issues, often delivered in a growled or screamed vocal style. Originating in the mid-1980s, grindcore bands like Napalm Death and Carcass helped define the genre's sound and aesthetic. Grindcore songs are usually very short, often lasting less than a minute, and the overall style emphasizes raw energy and a DIY ethos.