For example, my title is a quote from a book by Theodor Vischer, Äesthetic oder Wissenschaft des Schönen, published in 1840 - 1857. The title translates as Aesthetics or the Science of Beauty. I think I can see the problem just from the title. Why would you think that beauty could be reduced to scientific understanding? Well, of course an awful lot of people seem to be trying to do just that with MRI machines and statistics these days, but at least they have some scientific tools they are using. Poor Theodor Vischer seems to be trying to unscrew the inscrutable just with philosophical reasoning. And what does he come up with? Statements like this, from which my title is taken: "Music is the richest art: it expresses inmost things, utters the unutterable; yet it is the poorest art, says nothing."
I submit that if your method results in you coming up with statements like that, then your method is absurd! Music is a rich art indeed, that is rather a truism. So why do we think so? Certainly not because it utters the unutterable because that is simply a linguistic tangle. Music only "utters" or speaks in a literal sense when there are sung words, lyrics. And it is the lyrics that utter, not the music. Instrumental music is about the unutterable because it doesn't utter. It "musics". That is, it sounds melodies, rhythms and harmonies. That's what it does instead of uttering anything. Yes, music does indeed express, sometimes at least, "inmost things" but that is because those melodies, rhythms and harmonies resonate with us in expressive ways. How does that work? About the only way I know how to describe it is to say that, as a composer, when I find a particular melody, harmony or rhythm that resonates with me, that I respond to, that I find expressive, then I put it into a piece of music in hopes that other people will also respond to it. That is what we all do, I think, and it seems to work. If you want specifics, you have to talk about particular places in particular pieces.
I think this is where the philosophers fall apart, because this is precisely what they seem reluctant to do: to refer to specific musical examples. As Dahlhaus says:
[Eduard Hanslick] argued that the searching for the motivations of the forms of musical works in emotions adhering to them, or hidden in them, was fruitless. For forms, according to Hanslick, are always precise, firmly bounded, and concrete, whereas emotions remain vague, indefinite and abstract if they lack concepts and objects, yet such vague emotions are the only ones accessible to music. And from hazy generality nothing distinctly individual can be derived. [Dahlhaus, op. cit. p. 50]By "forms" he means, musical forms or structures. Musical structures are extremely precise as we can see from their notation:
So I am rather puzzled that philosophers seem to get themselves so tangled up over the aesthetics of music because all they really have to do is look at actual music and see how it is put together and how people react to it. This is the empirical data you need to start forming a theory of aesthetics. Some contemporary philosophers like Peter Kivy seem to be pretty good at doing this, but a lot of the historical texts on aesthetics go wildly astray in my opinion.
Let's listen to some music to end with. How about the piece that my example comes from? This is the Symphony No. 47 by Joseph Haydn: