@Aaron Maybe we're viewing aesthetics differently. Fux is very much about structure in my mind. There's a very clear definition for the melodies and harmonies and very strict view of consonances and dissonances sometimes to a fault in my mind. Those ideas can be and are applied outside the initial context maximize voice independence.

When I picture aesthetics and discussions about it in music, I think much more about someone like Debussy who no matter what the piece is, the exact structure isn't typically the topic. It's much more about how the texture, harmony, dynamics, rhythm, instrumentation, ect accomplishes a specific effect for the piece.

Not to say Fux doesn't have his own aesthetics, but for better or worse most people focus on the structural ideas and applying them rather than the specific aesthetics.

@Dom I don't think we disagree. Fux is motivated by a particular aesthetic, but certainly in the background of his treatise. Whereas, yes, discussing Debussy certainly brings aesthetics more to the fore, since he was specifically reacting against the conventions and restrictions of common-practice tonality.

Maybe in all this it comes down to the author's view on the "function" of music. Disclaimer, I really don't have a good certainty of Plato's positions, and would confuse them with other ancient Greek writings anyway. But if Brahms says "Art for Art's sake," I don't think Plato would. (Or maybe even wouldn't frame the argument the same way!)

All this business about playing a certain mode and making the general stand up from his meal and go to war, and playing a different mode and making him sit down again; it makes "music as medicine." And yet I don't think it's so much because they side with Wagner in the argument against Brahms, as that "absolute music" had not yet been objectified to the point that it was extracted from life.

I wish I knew more about the Greek(s) position on "the Art Object" in general. (When Keats ode-d to a Grecian urn, was he seeing the urn in the same way that it was by its creator? Beauty is truth, and that's all you need to know?)