Music is just layered simple patterns and our brains LOVE IT.
Sound is pressure waves, musical notes are a specific pattern of pressure waves. Melodies are repeated musical notes. Songs are repeated melodies following standard structure.
Our brains love trying to decode and parse all these overlapping patterns.
Maybe not really a shower thought and more wild speculation.
Imo it’s very unlikely that we grew to like music that already existed rather than growing to like audio patterns and then noticing we can make music.
Almost nothing in evolution happened sequentially. We almost certainly didn’t start creating music before our brains were equipped for it. Instead these things would’ve evolved in tandem. Each one driving the other, in a virtuous cycle.