Every time this happens,
immediately begin writing down everything about the music. Is it a track you have heard before, or an original piece? What kind of music is being played - and is there a pattern?
These are
things you need to know, and
have reference material on, if you want to figure this out. Your cognition is obviously compromised (you can tell because you're hallucinating - end of story) either because of cognitive constructs or a neurological problem, which means you can't trust yourself to correctly recall from long term memory. It's entirely possible your memory is working perfectly fine, just you can't
know that yet, which means your LTM cannot be trusted. Take notes, detailed notes.
For the next month, you should write down everything you can about every single hallucination you have - in fact, it would be best if you kept an actual and detailed diary, even if you think that's really gay, while going about your daily life and completely ceasing any attempts to 'fix' it for that month. In addition to the characteristics of the music, you need to know what happened throughout the day, what you did, how you were feeling right before it happened, how you were feeling right after it happened, and so forth. Everything is relevant, so don't be afraid to add new types of information to track as time goes by.
Above all, remember you're not only interested in mapping out your hallucination, but also why the hallucination happens. With this information, I'd start researching which brain center benefits from believing you are having music blasted into your ears when you're obviously not. Consult with your psychologist, show him your diary, and explain you're doing your own research because you can't afford, money or time-wise, to visit more than once or twice a month, as well as for your own peace of mind. A good psychologist will be supportive and try to limit the scope of your search to what's relevant.
With an objective methodology, at least half-decent foundation in psychology and neuroscience (I recommend you read the publications
Approaches to Psychology for psychology starters, my favorite base textbook right now, and the aptly named
Neuroscience for a basis in neuroscience), a good psychologist psychologist and dedication, you can change just anything.