The main problem with predicting the future is that it is assumed to be a continuation of the present. The 300 year time period being discussed is long enough to make that assumption false. The European hegemony will probably not exist. Political systems with individual freedom of choice may not exist. Cybernetic implants will alter what is considered human. Computer programming coupled with genetic advances may allow the creation of a vast number of new compositions by Mozart, Ellington or Bieber. Three hundred years ago the world's population was 600 million, there were no democratic governments, slavery/serfdom was the norm and the symphony orchestra had yet to evolve. It's a long time and many things can radically change.
The idea of good music is a manifestation of specific cultural norms. Today we can appreciate Beethoven because we can understand the world view that produced his music. In comparison think of how many participants in this forum cannot understand the culture that produces rap/hip-hop or other popular music forms. To them it's noise. Three hundred years from now without an understanding of how and why it was produced may render Beethoven as nothing more than noise. It's anybody's guess.
The idea of good music is a manifestation of specific cultural norms. Today we can appreciate Beethoven because we can understand the world view that produced his music. In comparison think of how many participants in this forum cannot understand the culture that produces rap/hip-hop or other popular music forms. To them it's noise. Three hundred years from now without an understanding of how and why it was produced may render Beethoven as nothing more than noise. It's anybody's guess.