Quote Originally Posted by Crushed Hope
By that definition than rock is a subgenre of jazz, which is a subgenre of blues. >_>

It isn't true. Musical instruments may be similar but they are played very differently, and I'd be damned if anyone can point me to a song that has guitars being played like Heathen, and still are rock.
Metal is a sub-genre of rock. So's punk, but punk is very different from other forms of rock. Don't make stuff up to help your 'I listen to metal and am therefore cool' superioirty complex.
Metal's a kind of rock. What's the big deal? It's just music, y'know?

Oh, and by your standars, fauvisism is not a form of post-impressionism because it differs from pointilism. (I can be smart-assed and elitist too).