The ’80s were both a productive and a tumultuous time for heavy metal. The music underwent huge leaps in speed, volume and aggression. Early in the decade, New Wave of British Heavy Metal pioneers Iron Maiden, Judas Priest and Motörhead represented the genre’s vanguard thanks to their careening tempos and screaming fretwork. Yet in just a few short years they ceded leadership to thrash’s Big Four (Slayer, Metallica, Anthrax and Megadeth), whose violent shredding, double bass drumming and apocalyptic lyrics ushered in extreme metal. While all this was happening, headbangers’ fascination with Satanism and sleaze ignited waves of condemnation. In addition to religious leaders painting Ozzy Osbourne—who released one of the decade’s greatest albums in Blizzard of Ozz—as Lucifer himself, the Parents Music Resource Center set their sights on hair-metal bad boys like Mötley Crüe, who in their eyes represented the decline of Western civilisation.