Jim, I think I would agree with you that just by probability alone, the best "talent" probably has not risen to prominence but I'm not talking about "potential". I could be wrong of course but do you think there was someone much better than Beethoven in his age who we never heard of? To write at that level, he would need support from the wealthy and the professional musicians of the day who presented the concerts. So being in the "Nashville" of classical music, which was probably Vienna, was almost a requirement just to get a chance to write. The Eagles needed the collaboration of many to make the amazing songs they created. I think that raw talent without some kind of collaboration would never be heard even locally. Even you have your band, and I bet you appreciated them. I spent a couple of hours today laying down some tracks on a new song and it is as tedious as hell. I hate it compared to that summer in Nashville when I had 4 session musicians "reading my mind".
I think the very best music may very well rise to prominence most of the time because it takes so much collaboration for the really good stuff to come together. But if Mike Dunbar is correct, somewhere in the back hills of Kentucky, there is probably a little bluegrass band turning out gems we will never hear.

"Imagination is more important than knowledge." - Albert Einstein