I have to agree with gollymolly on the "disheartening" aspect. I think that it might be better to agree that there are two sets of opinions here. And that both do have a right to feel the way they do - even if the opinion isn't shared.
But I also think that there could (maybe?) be some kind of compromise taking place if you were on the plane? What that would be, I don't know off the top of my head. But surely there's something that, while doesn't completely satisfy both parties, does make things a little less stressful?
And I do stand by my comment that, if you have a medical condition, it really is important that you speak up as such. If hearing the music would cause you uncontrollable pain, I can't imagine any rational person's saying, "Well, we're going to do it anyway." I would think that most people would, hopefully, realize that a person's health is first and foremost.
Does everyone have to enjoy the music? That's kind of a silly question. There are many genres of music for a reason; everyone loves a different sound. What appeals to me isn't what appeals to you. But is it possible to listen to another type of music with respect for those playing? Of course. Everyone here would do so, I'd think.