Heavy metal has came in the last 40 years. And while it at first was just more aggressive rock, it has since morphed into something completely different and original. Sure, it's more a combination of hard rock with blues elements taken out of it and replaced with classical elements, but it's a different kind of music all together. Take black metal for example. Whether you like it or not, it is unrecognizable from rock music. It has elements of classical music and melody thrown in in a way that is totally unique and does not resemble anything else.

And as for blues music, I think it died with Stevie Ray Vaughan. Sure he didn't invent anything, or do anything TRULY innovative, but the style and intensity with which he played made it SEEM like a new experience and has not been replicated since his passing.