The Platonists belive mathmatical entities exist independently. Schopenhauer believed music would exist after the end of the world. I think that was in Stella Maris. Which you might enjoy, if you like this sort of thing. I loved it so much when it finished I went right back to the beginning and started over, then again a week or so later. Just finished for the third time today in fact. It helps if you first read The Passenger.

Listen to The Passenger by Cormac McCarthy on Audible. https://www.audible.com/pd/B09TLBRQ29?source_code=ASSOR150021921000V

Listen to Stella Maris by Cormac McCarthy on Audible. https://www.audible.com/pd/B09TLDW39R?source_code=ASSOR150021921000V