All photos from MetOnTour.com unless otherwise noted.

Thousands packed stadiums across Eastern Europe as the fabled "Big Four" of American thrash metal — Metallica, Slayer, Megadeth, and Anthrax — shared a stage for the first time. International interest resulted in one tour stop being recorded, edited, and beamed to movie theaters across the globe to an estimated 100,000 viewers.

I set out, rather cynically, to placate my inner 15-year-old's devotion to these bands. My more inquisitve adult side wondered what a metal concert in a movie theater would be like? Traditionally, yelling at a movie screen is usually reserved for slasher flicks and midnight screenings of Rocky Horror Picture Show. Would people get out of their seats and engage in usual concert behavior — lyric-shouting, air instrument-playing, moshing and the like?

As far as the bands go, I anticipated four hours of ho-hum performances by once-great metal legends. Early audio problems during pre-show interviews led to MST3K-style commentary from the peanut gallery such as, "Hi, my name is Lars and I am slowly unlearning how to play the drums." I drafted my own quips and wondered how long the next four hours would drag.

But thanks to the great guitarists in these bands, I was reminded, riff by riff, what makes heavy metal so enduring and powerful. (Video of the historic 'Big Four' performance, and setlists from each band after the jump)

This article appears in Jun 24-30, 2010.