- Do you agree that from experience and observation, we can tell that certain genres or fields appear to become completed?
- Does this concept or another concept best explain what is happening?
I think two of your premises aren't necessarily true:
So if I hit random piano keys with my hands a few times and call it a song, the consensus of music listeners would be that Beethoven's Fur Elise is a better song.
Probably, but I think your example is a little bit too extreme to demonstrate your point. There are a lot of genres, like taarab, that won't sound like good music to you because of your cultural background. Acid house probably wouldn't sound good to people who were raised in the 1800s, either. There are commonalities between how people appreciate music, but people come up with new ways to introduce musicality to a piece really often, which means that it's hard to enumerate all the songs there could be.
If atonal or microtonal music suddenly got trendy, you'd come up with all kinds of new tone patterns we didn't have before. If people started thinking about timbre differently, we could come up with instruments we don't know how to listen to now. Both of these things happened after the first synthesizers came out. I don't think you can predict in advance what will make people think "this sounds good."
the general consensus is that the best classical artists are from over 50-100 years ago
The great classical artists of the time of Debussy and Ravel were musicians like Chopin and Beethoven. The great classical artists of the time of Stravinsky and Schoenberg were musicians like Debussy and Ravel. Reich and Glass had Stravinsky and Schoenberg. (and maybe Gershwin), and now we're venerating Reich and Glass. Arvo Part is probably going to get canonized real soon now.
I think that when you're talking about "classical music" you're talking about music that most people are only exposed to in curated form. It seems like when that happens, curators stick to examples that are really broadly accessible, which isn't a good way to get a picture of the whole genre. The last trends of really broadly accessible music were 1800s romanticism and 1960s minimalism, and 1960s minimalism doesn't seem old enough for curators to put it on the classical music shelf.
It's not like painting ended with Da Vinci, but today's public doesn't particularly like Liechtenstein, Warhol, Rothko, Picasso, and so on.
This doesn't undermine your point, but I think you might want to investigate modern concert music a little more before you make some of these assertions.
I don't mean to press you on a point, but when you say in reference to musical consensus, "Probably, but I think your example is a little bit too extreme to demonstrate your point", I think it is important to say whether you believe there is any musical consensus of what is good, or if you believe there is zero consensus. The degree does not matter as to whether the point I'm trying to make is true. Is there any consensus based on how shared human nature interacts with physical sounds as to what is agreed upon as "good"? It seems diffic...