Yeah, but......
Its definition is definately more than a little vague, and if I go by the format of the two "classic rock" radio stations in my town, it consists of way too much arena rock and bad hair bands. Further, the obsessive airplay of certain songs has virtually knocked them off my personal play-list.
I really don't need to hear "Layla," "Smoke on the Water" or "Tumbling Dice" seven times a day.