Once again, the stand-up swinging duo known as 2CELLOS has nailed a cover of a classic tune.

This time, they take the Iron Maiden staple "The Trooper" and turn it into something so insane, you can't help but slam your head while throwin' up the horns. The video is "official" - which means it's all set up. You would figure that most people would know that, considering that their cellos change in mid-note, but some people aren't that savvy...