Metallica's rise folded right in with the groundswell of thrash, hoovering up disaffected punks who weren't in on that genre's merger with New Wave. Ditto for the splatter crew of Slayer, who took their shared interest in the horrors of real-life gang violence, serial killers, and global conflict, and funneled it into a musical aesthetic of tormented shrieks. By the end of '83, both had issued debuts (Metallica with the timelessly rad Kill 'Em All, Slayer with the garishly satanic Show No Mercy) that would mark the start of thrash's ascendancy.
Prior to thrash, heavy metal was a subset of hard rock, at least in America: a band like Black Sabbath would, throughout the 1970s, share stages with Yes and the Eagles and the Ramones. Metal existed mainly as a flavor of rock, an extreme end of a spectrum that started with folk rock and extended all the way past Deep Purple and Grand Funk to the power-mad embryonic metal-ry of Uriah Heep, Ted Nugent, and Motörhead. But it took the enforced intensity of the so-called New Wave of British Heavy Metal, a late-'70s incubator that spat out, in addition to the aforementioned Priest and Maiden, such luminaries as Def Leppard and Mercyful Fate, to really up the ante in terms of pure toughness — and for metal culture to begin willingly ghettoizing itself.
Thrash metal threatened society in ways that may be hard to fathom now. Music had been shocking or antisocial in decades prior, but in the gory satanic themes and relentlessly hostile attitude of the rising thrash tide, straight society saw a rock-and-roll enemy that needed to be put down. But mainstream culture would never have cared about metal's pernicious influence if the genre wasn't on a seemingly unending rise in popularity.
In fact, the outright hostility that thrash received from critics and tastemakers probably did more to fuel the fire of the genre: after all, the condemnation from the mainstream dovetailed so perfectly with the sort of woe-is-me-against-the-world narratives that these bands were penning, from the suicidal epic strokes of Metallica's superb "Fade to Black" to Megadeth's ode to metalhead persecution, "Peace Sells." Metal is both an outsider musical movement and a populist one: a true metal fan is in his element when raising his fist in defiance of society's conformity, but usually amongst a sea of like-minded individuals in thrall to the same idols. This explains how, without radio, MTV, or mainstream press, the Big Four, like Maiden and Priest before them, all ended the '80s as huge, shed-filling marquee acts. Metal had become big business.THE SKULL BENEATH THE SKIN
Inevitably, popularity led to acceptance: along with punk and rap, '80s metal slowly but surely became normalized. What was shocking at the beginning of one decade became the standard for teen rebellion by the start of the next.
Only when the genre splintered into death metal and black metal in the '90s did it become truly dangerous again. While American metal was becoming subsumed by the fuzzy toothlessness of grunge, Scandinavia became the new proving ground for metal's self-marginalization. Black metal had been evolving since the '80s, influenced by the same Venom and Mercyful Fate records that young American thrashers stole licks from. But by the early '90s, as Metallica took the riff from Excel's "Tapping Into the Emotional Void" and spun it into rock radio gold in the form of the soon-ubiquitous "Enter Sandman," Scandinavian crews like Mayhem, Burzum, and Bathory were toiling over a bubbling cauldron of rapid tremolo picking, lo-fi self-production, King Diamond–y face paint, and an obsession with pre-Christian mythology.