Alternative Metal is a subgenre of metal music that emerged in the '80s and became popular in the '90s. It combines the heavy guitar riffs and energy of traditional metal with influences from other music genres such as alternative rock, grunge, funk, and hip hop. It is often characterized by the innovative song structures and experimental nature, offering a more unique and diverse musical experience. Popular bands of the genre include Tool, Deftones, and System of a Down.