The first people Metallica thanked when they won a Grammy Award in 1991, for what became known as The Black Album, were the progressive rock band Jethro Tull. Not because of their inordinate influence on Metallica, or even because Metallica felt a kinship with them—but because Jethro Tull hadn’t put out their own album that year to stand as competition. Tull had infamously won the award for Best Hard Rock/Metal Performance in 1989—a reflection of both the Academy’s disconnect with metal culture and how uneasily it sat in the mainstream. And while The Black Album’s win didn’t constitute acceptance, per se, it acknowledged what fans of the band had understood for going on 10 years: Metal was the vanguard of hard rock, and Metallica was the vanguard of metal. Drummer and co-writer Lars Ulrich says they used to labour for hours over the perfect take, Frankenstein-ing together fragments of drum parts, punching in riffs, blending and overdubbing until every wrinkle was ironed flat. They wanted precision, and by precision they meant technical mastery—a superlative in a world where the goal is to play as hard, fast and complicatedly as possible without slipping. And it isn’t that The Black Album isn’t complex. But whereas tracks like “One”, “Master of Puppets” and “Seek & Destroy”—songs that not only defined Metallica’s sound, but the sound of ’80s metal in general—foregrounded complexity as proof of the band’s stamina and ambition, the music here is streamlined and the performances natural. Ulrich says producer Bob Rock helped them understand their recordings not just as seamless stacks of riffs, but as shapes with ebb and flow, rise and fall. In the songs’ simplicity is a clear confidence: “Enter Sandman” and “Sad but True” are two of the heaviest tracks the band recorded, but also two of the most straightforward. “The Unforgiven” evokes Celtic folk and the majestic spaghetti Western soundtracks of Ennio Morricone (whose “The Ecstasy of Gold” long served as their walk-on music), but it works just as well around the campfire. James Hetfield wasn’t sure whether “Nothing Else Matters” even belonged on a Metallica album—it was so personal, so disclosing. But they’d always trusted their gut, and in doing so helped revise Led Zeppelin ballads for the post-punk era: They thrash, but they do it with tenderness.