Mmm. Pigeonholing is about reducing, exactly the opposite in fact of what I was suggesting in the other thread.
I love rock music and pretty much everything that falls under that very broad spectrum. It's what I was brought up on and is part of me. I just don't see the point of all this sub-divisional mumbo jumbo. As @stewblack highlighted, Wikipedia has an interesting take on it. I was looking at what they include under Heavy Metal - 'doom metal', 'pirate metal and 'avant-garde metal'. All smoke and mirrors to me.