Take out Sean Harris’s shriek, tune down and speed everything up slightly, and hit the lights: if you’re wondering where Metallica learned to Metallica, look no further. This shocking debut defined the New Wave of British Heavy Metal more than just about anything not released by Iron Maiden or Def Leppard. The two electricity-based tunes crackled with high voltage, but of course it’s “Am I Evil?”’s ruminations on inherited sins and warranted vengeance that struck hardest.