but other than an exercise to increase one's harmonic knowledge, i still am at a bit of a loss to see the benefit of harmonic analysis.
Harmonic Analysis shows how a given piece adheres to or deviates from the norms of particular style. It's simply comparative analysis in that regard.
It may also reveal deeper structural underpinnings not obvious on the surface texture.
It may also point to a composer's ingenuity, or master of the style, or stylistic idiosyncracies, and so on.
In the context of Common Practice Period music, one should understand that a harmonic analysis is about the *functionality* of the music, not just "naming the chords".
It's the difference between defining words, and understanding grammar and syntax. It's about knowing what the word "sow" means in a sentence.
It could be a pig, or it could be to spread seed. Which is it? Calling a chord E7#9 is like simply telling us what letters are in the word. But understanding harmonic function is akin to being able to understand which meaning of "sow" the author means.
And just like authors can make double-entendres, and play word games based on the expected meaning of a word versus how it's used, so too can composers do with sound.
For example, we expect a V7 to resolve to I, but when it resolves to VI it's kind of a surprise. And the whole reason this works is we understand that there's this expectation and it's being thwarted. So while music may not have the huge depth of meaning that words/grammar can produce, it can do very similar things. Theory is that Grammar. It's not spelling.
perhaps it would be of some benefit to composers who are looking to create a similar feel to an analyzed piece. but harmonic analysis seems less applicable then, say, the rules of counterpoint.
it's main purpose strikes me as theoretical, but i'll keep pondering it.\
Well, they do call it music THEORY!!!!
Theory is DESCRIPTIVE not prescriptive. It's not about the rules, it's about the TOOLS.
Yes, it is true that if you'd like to compose in a style like, say, Sor, analyzing his music (as well as his personal style) will give a person the tools necessary for emulating Sor's style effectively.
You have to stop thinking about "chords". It's not about chords. It's about functionality.
A sentence has meaning. You use letters, that make up words, within a grammatical structure, that most effectively gets your meaning across.
A musical phrase has function. You use notes, that make up chords, within a harmonic progression, that most effectively gets that function across.