http://www.abqtrib.com/news/2007/nov/01/steve-brewer-whats-grunge-and-jams-flannel/
And, an opposing point of view...
http://www.youtube.com/watch?v=q9Z79eHaaEI
I HATE grunge, thus I offer yet another opposing point of view: http://www.savoirvivreny.com/2007/08/grunge-resurrection.html
^ That I would characterize as "post-grunge", since if it was genuine (and early 1990s) both the man & girl would be dressed identically, and neither's clothes would be clean or at all fitted.