When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Fin Costello/Redferns/Getty Images Friday, January 13, 1984 was a bad day for Metallica.

While Slayer, Exodus, and others were also pioneers of thrash metal, Metallica’s first two albums created a dividing line in music history. Once Metallica had arrived, they established a new blueprint ...