@tablejockey,
"Nothing contemporary or in the last 40/50 or so years is close to the level of PS-at least in how it influenced musicians who listened to it when it was introduced."
Is such a thing even possible now?
Or have all of the undiscovered musical discoveries and developments been discovered and developed?
As a chessplayer I've noticed that since the age of computers very few meaningful novelties (previously undiscovered strong moves in known opening positions) have been found.
This, despite the advent of supercomputers and neural networks which can play the game at far more accurate levels than any human could dream of.
Perhaps music, like chess, seemingly infinite in its expression, is also ultimately finite?
Thankfully, we are not infinite, and we have plenty of music to easily fill a lifetime.