Musical Anhedonia
No pleasure from music, in a person with normal hearing, normal music perception and a normal reward response to other things. Specific, not general, which is what makes it informative.
What it is
The reward machinery works. Money still motivates. Tunes are still recognised, rhythm is still tracked, a wrong note is still heard as wrong. What is missing is the reward that ordinarily follows from all of that.
It is rare, and it is the cleanest available constraint on any account that treats musical pleasure as an automatic consequence of hearing organised sound.