"Like most genres, [metalcore is] not an easy term to define; even saying “metal meets hardcore” doesn’t really do it. Hardcore and metal’s relationship long predates metalcore; hardcore bands inspired metal bands to invent thrash, and in turn thrash bands inspired punk bands to start crossover thrash, both genres influenced grunge, and the cross-pollination just kept spiraling from there. I don’t know the exact year that “metalcore” entered the vernacular, but some of the earlier bands [...] probably would have just been called “metallic hardcore.""