Cobain didn't revolutionize as much as he angrily responded to the current state of popular music
Cobain's genius was in his way to satirize and use irony to piss people and make them think at the same time
he also was able to come up with simple songs that compilemented his very melodic/complex melodies
Cobain also, unfortunatly inspired a generation of whinny bitches who think their life is so hard and no one understands them and they are so tragicaly beat down by society etc. bull**** etc. bull**** etc...
when i first looked at this post I thought how stupid it was, but once i started thinking about it I find it hard not to think that Cobain did, in fact, have a bigger influence on popular music than Hendrix, whose influence didn't go much beyond guitar playing
Alas Gandalf lives, Middle Earth is again safe...