Whether you like classical music or not, it's complexity and power are undeniable.  The same can be said for metal.  Check out Pete Sandoval, long time death metal drummer, performing Mozart's 25th symphony. 

 

I've got to assume if he was alive, Mozart would dig this.  The 25th Symphony is one of his more well known works, and it sounds pretty bad ass with that beat behind it.  Pete Sandoval has been a fixture in the death metal scene forever, playing with Morbid Angel and Terrorizer.  This combination of Mozart and metal seems so natural, I'm surprised you don't hear this more often.