There must have been a moment when the total recorded output of the world surpassed the total time a person, a city, a country (have we reached that point yet?) could listen or consume all of them. I suspect we will reach a point where songs are played once only, never to be heard again.
Combine public domain growth with Sturgeon’s Law, and you need 10x lifetimes of material in order to have a full lifetime’s worth of good material. Increase that to 100x to have a full lifetime’s worth of great material.
Working against this is the “sliding window” effect of older materials becoming less relevant to modern audiences, and hence “less good”.
Counter this with longer cultural continuity that turns the sliding window into a stretching window.
