I noticed that music sounds different when you start listening to it half way, it doesn't parse as the same song for an instant and is a jumbled mess of sound.

I don't listen to a lot of music but when I do I put the same song on repeat, and I noticed that after some hours of the same song, I start to hear components of the song that I wasn't even aware of before.

It's like my brain has been retuned to a different layer.

This usually coincides with the music losing its magic around this time so I have to move on to another song.

It almost seems like the song is a puzzle and it gets slowly decomposed and pulled apart so I can hear more of it at once.

I frequently hear songs in my head, so the internal version of the song wouldn't contain the subtleties that only emerge after hours of listening.

So maybe when the song loses its magic, I gain the ability to hear all of it in my head.

Maybe the magic of a song comes from the difference between what you can consciously process and the total stimulus.

Over time you learn to consciously process (compress?) more of the song.

I find it quite strange that music even exists, I'm sure these aren't very original thoughts and I don't know or care much about music anyway.