I think the part of our brains that enjoys music only has short-term memory and is experiencing the pattern-breaking surprise every time, even if you remember t

I think the part of our brains that enjoys music only has short-term memory and is experiencing the pattern-breaking surprise every time, even if you remember the song consciously. I'd say it's even over time trained to recognize the patters it encounters quicker, so the songs become MORE enjoyable the more you listen to them (up to a point).