Music theory for nerds

I spent a long time researching where Western music "comes from". One important thing to understand is that the key feature of Western music is harmony. This is not the case for most other musical traditions. Harmony comes from a layering of independent melodic lines (called voices), such that they evolve in ways that create and resolve tensions. This is called counterpoint.

The ways in which these tensions resolve are called cadences, and classical music was all them. Musical form arises around how a piece of music is organized to have an arc (and arcs of arcs) that leads to a cadence. It's kind of like how there are only a few basic narrative structures in storytelling, yet infinite variations in types of stories.

The tension between the sounds in concurrent melodic voices emerges from the structure of the sounds. Harmonic sounds, like ones produced from wind and string instruments, sound good (consonant) when their fundamental frequencies are simple ratios. This is largely because of how the human auditory system works.

Our scales and chords come from picking collections of notes that approximate simple ratios. We deal with approximate ratios using nth-roots for two reasons. First, simple ratios don't compose well -- stack them (i.e. multiply them) and you get ratios that aren't so simple. nth-roots do stack nicely. Second, it lets us merge nearby flat and sharp notes. This wouldn't be possible if we used real ratios. That merger, known as enharmonicity, lets us do all sorts of cool compositional tricks that are generally considered more worthwhile than the slight improvement in sound quality we'd experience by using the real ratios. There are various ways to pick just which notes merge, but by far the most popular approach is to use 12 notes.

So, this is where we got our notes and scale from. This happened around the year 1800, give or take a couple decades.

The history of Western music since that point in time largely revolves around coming up with new ways to play with those 12 notes, in many ways erasing the musical features that caused the 12 notes to emerge in the first place. This is why the system of note names, with the flats and sharps, feels rather arbitrary today.

Unfortunately, there are not a lot of great resource that tell this full story. The two books I found most enlightening in piecing together the "real story" are:

- Tuning, Timbre, Spectrum, Scale: https://www.amazon.com/Tuning-Timbre-Spectrum-William-Sethar... - A Geometry of Music: https://www.amazon.com/Geometry-Music-Counterpoint-Extended-...

Do you have examples of musical traditions that don't do this? Both the Indian and Chinese musical systems do something similar.

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I'm not really sure if this post is "wrong". It gets the chronology mixed up a bit -- talking of twelfth roots of two before talking about ratios, but I thought that was just done to help explain things by reverse-engineering them. I don't think it claims that the notes "came from" roots of two.

Every element of Western music builds on the same building blocks. Western harmony, as taught, relies on understanding chromatic and diatonic harmony; the author did a nice job figuring out and explaining the compromises inherent in equal temperament (without knowing about how ratios and tuning worked before equal temperament; people didn't always fudge the ratios to make them work out the same across all keys), which is cool. But, he still doesn't actually know much about western musical harmony, as evidenced by the assertion that C Major and A minor are "the same", because they share a key signature and the same notes. Had he known that equal temperament is a moden-ish invention, he might have also figured that C Major and A minor actually have (slightly) different notes if your instrument is tuned specifically for that key rather than with equal temperament.

In short, he's just not done learning yet. Most musicians and composers never really are, as it is a vast subject. And, what he's calling "music theory" is really more "equal temperament tuning math" with very little theory.

Not to say it's not interesting and well-presented. It may be useful for non-musical nerds to see it presented in this way.

I believe the Solfege named intervals (Do-Re-Mi-Fa-So-La-Ti-Do) are only taught as a historical oddity these days (or maybe used more in classical training?). All of my musical instruction, at the high school and college level, used numeric interval names (1-2-3-4-5-6-7-8). Most of the serious musicians I've played with also used the numeric scale rather than Do-Re-Mi. We learned how to sing Do-Re-Mi, "Just in case", but we never used it.

Were you taught in the US, or somewhere else? Maybe it is a regional thing.