You feel it building in your muscles, a tension crying for release.  Your fists clench, and your feet move. The strain spreads into your back, snaking up your spine. Before you know it, you’re thrusting your head forwards, pulling sharply back, your hair flailing. “BANG YOUR HEAD AGAINST THE STAGE, LIKE YOU NEVER DID BEFORE, MAKE IT RING, MAKE IT BLEED, MAKE IT REALLY SORE!” And you’re gone, lost in wild abandon, part of something primal and bigger than yourself. This is 1983, and you are a fan of the greatest thrash metal band the world has ever seen: Metallica. From…