Interesting stuff, goyacobol. When I listen to heavy metal, to me it is percussive based, not really melody based. It almost sounds like you have 4 or 5 drummers on the stage. And looking at the breakdown of Jones' technique, it looks like that is what he is trying to accomplish.I am an old dude and I have trouble understanding some of the heavy metal stuff. Tool is for me a little monotonous in some respects but I can appreciate the nerdy technical skills involved in the guitar parts. I just like more melodic music but that is me and not everyone has the same musical tastes here. I am trying to learn what it is that draws us to a certain genre of music. I think every generation wants to create its own style as a form of breaking away from the nest so to speak. How we can put all that together and still arrive at some unifying "style" I really am not sure but here is one guitar teacher's explanation of the Tool guitarist's (Adam Jones) method:
All that percussion can create a powerful sound, but also can be quite dissociative because of the use of odd time signatures. IMO.