"OV" by Orthrelm
Whether or not this is truly a song is up for debate--at over forty-five minutes it fills an entire album--but I don't really care about that. What I care about is that "OV" is one of the more impressive pieces of music I've heard. Its minimalism is hypnotic despite it being painfully aggressive and extremely heavy, and that it doesn't let up even for a second proves it to be an endurance test for anyone with a pair of ears. What's most impressive is that it's the work of two men, a guitarist and a drummer, and they play at speeds and frequencies that most accomplished musicians just can't replicate. And they play this way without stopping for the better part of an hour.