There should be a frame of reference that is common enough to all community members that musicians of exceptional talent can excel, and be recognized. This does not have to be mere technical ability, but can also be ability in perfecting a tonal quality, in composing a new song, or in the degree of emotional expression. I'll assume for the moment that we can mostly agree on these points. I don't know enough about it to say, and perhaps Miekal can provide more information. More on that later.
Some instruments are expensive and rock'n'roll generally requires electricity.
Let me elaborate on that just a bit. The amount of money that had to be thrown around just to have your music be considered legitimate was unbelievable. Truly, this WAS a case of corporations manipulating public taste, because in those days, if your music wasn't audibly expensive, it wasn't going to be heard by anybody. And you certainly couldn't play that sort of thing around a campfire. However, those days are over.