System of a Down were grouped into the late-‘90s nu-metal scene, but their penchant for experimentation quickly became apparent—and impossible to categorize. The band built an audience with their eponymous debut, as fans of prog rock, alt-metal, and hard rock all gravitated towards Serj Tankian's schizophrenic vocals and Daron Malakian's riffs that channeled everything from Zappa to the band's Armenian-American heritage. 2001's Toxicity turned SOAD into alt-rock household names, and they would go on to release three more LPs before taking a hiatus, returning to live duty in 2011.