> but you can't start from the harmonic series and find your way to Western classical music.
You absolutely can, because that's essentially exactly what western classical music (and more or less all other forms of music) already did, just spread out over a very long period of time.
That's the wrong way about thinking about it, though. Historical processes don't operate solely based on first principles, they operate according to contingency.
Take Western music. Early music is mostly vocal, and early principles of music theory evolved around what would be possible (and practical) to sing. Different people have different vocal ranges, and the constraints that puts on the music lead to certain constraints in counterpoint. Eventually instrumental music becomes more socially important, and that changes what kinds of music can be made. Mathematics progresses in such a way that new tuning systems (12 tone equal temperament, and its precursors) make it easier to modulate between keys, and more modulation (and chromaticism) becomes common.
Even things like the way the music is structured depend on social practices, they're not spontaneous. The sonata form depends on an audience that listens attentively to music so that they can perceive the way the themes are gradually transformed.
I could go on, but nearly everything in music goes this way--there are principles, but they only have a limited explanatory power, you need to get into historical contingency to really understand why things evolve the way they do.
I never said that it was necessarily a smart way to think about it. But just as we don't reach the periodic table by taking children through every process and discovery that led to uncovering a new element, it's not necessary to teach this subject (whatever we call it) as a historical process either.
I certainly agree that historical context has always been central to the way music has developed. It's not for nothing that most of Europe refers to "the church modes" rather than using a more abstract term for a set of interval rotations. But that historical context is only absolutely necessary if you want to try to understand why music evolved in the way that it did. It's not necessary if your goal is to understand the way we understand, compose and perform music today.
Of course, I'm all for more understanding of music, so I'd favor historical context every time. It's just that it's not a necessary feature for understanding where we currently are.
The analogy with chemistry doesn't work. There is only one "chemistry theory": the one that describes reality. The table of elements changes because our experimental understanding of reality improves.
There is no one true "music theory". Music theory as it is typically taught is no more than an elaborate system of nomenclature of the stylistic preferences of European music in the last three centuries. It is a cultural description of a cultural phenomenon.
To get into more specifics, when explaining music theory at an elementary level, you might say that a frequency ratio of 1:2 is called an octave and all the notes with an octave relationship to each other are considered equivalent. That is true, if you are making European-style music. Most other cultures around the world have a name for the interval called the octave, but most of them don't consider all octaves to be the same note. "octave equivalency" is fundamental to Western music, but it's not a universal law, it's a stylistic choice. To imply otherwise by claiming that your explanation of this European convention is essential to music writ large is to do a disservice to the many musical cultures around the world that don't follow that convention.
> The harmonic series is relevant, but you can't start from the harmonic series and find your way to Western classical music.
As big as fan as I am of being aware of non-western musical culture, I was commenting on the specific idea of moving from the harmonic series to a specific musical culture (the western classical one). This is why the chemistry analogy is (roughly) appropriate, because there are in fact a substantial number of (western) music theorists who consider there to be only a single western classic music theory.
I try to almost never use the words "music theory" without prefixing them with a temporal and/or geographic cultural qualifier (though I likely often fail here).
You absolutely can, because that's essentially exactly what western classical music (and more or less all other forms of music) already did, just spread out over a very long period of time.