I listen to the same music by the same bands pretty much every day. I find comfort in knowing every note and beat. I’m excited to hear an element I’ve never heard before.
Maybe it’s very faint harmony. Sometimes it’s learning that the vocal track fades from left to right in a subtle way.
The longer I’ve listened to these songs, the less there is to discover. Until suddenly… a new sound. New to me and, perhaps, new to nearly everyone else who has ever heard the song.