You've asked several questions here, but I'm going to pick the one I think I understand and go with that! I'm a practical sort, and I can't always participate in the philosophical discussions, although I love to read them.
How is there any single experience that is better than another? Well, there just is.
I took a writing class once in which the class was supposed to get together and define art. And not only define it, but do so in one or two sentences. I mean, one of the great questions of the ages, wrestled over by the greatest minds who ever lived, and our little class, most of whom had never even seen a well-done painting, was supposed to solve it. Well, it turned into a discussion, then a debate, and eventually a war, and the teacher called off the assignment because things got so ugly. To spill into another question, no, I don't think there's absolute music. I mean, there's music, and there's whatever people do with it, taking into account about a million variables. To whatever degree they are informed about it, care about it, physical skills, mood o' day, quality and type of instrument, personal opinion, level of bravado or lack thereof... But to ask how there can be any single experience that is better than another sort of implies that there really isn't. And yet there certainly are some performances and experiences that are better than others. If you take a 19-year-old who is gifted but, of course, young, have her perform a musical work of great depth, like some big Bach or something that she can technically accomplish, then flash forward thirty years and, assuming she's kept playing and growing and is having an interesting life, have her perform it again, you will probably have something better. Maybe profoundly better. I mean, if there is no "better" to attain to, why are we all working so hard? If it doesn't matter what we actually sound like, just what we intend or want to sound like, and the listener is just having his own inward experience anyway, why should I practice? Well, actually I don't, haha, but I SHOULD, and why is that? Because if I do, I will have a better experience for myself and give a better experience to the listener.
Am I missing the point of the question? Because usually I see many sides to an issue, but I really don't on this. Which may mean that I totally don't get it. Anyway, cheers.