Despite what the nomenclature would have you believe, alternative metal isn’t simply a mash-up of alt-rock and headbanging heaviosity. In fact, alternative influences are not an essential component to classifying alt-metal bands. Alternative metal began to emerge in the 1980s as disparate left-of-center heavy metal groups dabbled in styles outside of hard rock orthodoxy, including funk, hip-hop, industrial, and, yes, alternative rock. The genre began to codify in the early 1990s into a modernist strain of metal that emphasized aggression and texture over melody and traditional hard rock lead guitar, a fortuitous development that allowed it to gain commercial ground at the same time thrash and grunge were redefining the boundaries of what sort of heavy music could garner mass appeal. Though its descendant genre, nu metal, would largely forgo its adventurousness and idiosyncrasies for rigid formula, alternative metal is still a vital force well into the 21st century, as its influence is so pervasive that its sonic hallmarks practically shape the sound of contemporary hard rock radio.