The 12-tone system captures most small natural number ratios and, as such, covers most non-western note systems as well (allowing for temperament differences).
It's safe to say that less than 0.1% of all music and all composers or performers ever used anything else, and they wouldn't be using synthesizers for that task.
> "The 12-tone system captures most small natural number ratios"
Notably absent are any ratios that involve a power of 7, and ratios that involve a power of 5 are noticeably out of tune.
> "and, as such, covers most non-western note systems as well (allowing for temperament differences)."
Temperament differences are pretty significant.
> "It's safe to say that less than 0.1% of all music and all composers or performers ever used anything else"
I don't know how many composers and performers are interested in carnotic music, Indonesian gamelan, traditional Turkish music, western music as practiced more than a couple hundred years ago, barbershop harmony, lap steel, slide guitar, Appalachian dulcimer, and so on but I think 0.1% is very much an under-count.
Even if you're 100% focused on mainstream western music, guitarists will do things like tune their G string 15 cents flat or so because it sounds better for some chords. (I haven't tried that one. I prefer to just replace the fingerboard, re-arranging all the frets so I can play guitar in proper just intonation.)
> "and they wouldn't be using synthesizers for that task."
Well, that's the problem right there. Synthesizers should be the first choice for microtonal music, not the last one. There's no technical reason for synthesizers to be biased towards 12-EDO or any other specific tuning, it's just a historical accident that the protocol we use is one that wasn't designed with any other use case in mind.
>Notably absent are any ratios that involve a power of 7
Except the tritone that's 1% off 7/5.
>ratios that involve a power of 5 are noticeably out of tune
Depending on your definition of "tune". Regardless, pitch bends cover that if needed.
>Temperament differences are pretty significant.
And one's free to implement whatever temperament in midi, in fact even consumer pianos allow that. If there was any semblance of demand for that midi would spare an event for that.
>carnatic music
Show so much variability between players that it's safe to approximate their microtones in 12 notes, with bends if desired.
>barbershop harmony, lap steel, slide guitar, Appalachian dulcimer
All serviceable in the 12 note system.
Even early pianos were tempered for a particular key until common sense prevailed.
>it's just a historical accident that the protocol we use is one that wasn't designed with any other use case in mind
If entire countries cede their musical theory systems for a foreign one it's not a matter of an accident, it's an indication of superiority.
>There's no technical reason for synthesizers to be biased towards 12-EDO
Yes there is, it's exactly because near 100% of their users want just that. Most midi devices don't use anything past velocity and pitch bends, complicating them to include non-12 note systems would be a total flop.
That's technically true. 7/5 is about 99% of the square root of 2, but in terms of pitch intervals, a difference between 582.52 cents and 600 cents is about 17.49 cents. That's not necessarily terrible -- it's not that much worse than the difference between a just major third and an equal tempered major third, but it's not great either.
Other useful intervals like 7/6 and 7/4 don't really have any close equivalent in 12-edo, though dominant seventh chords do sort of imply a 4:5:6:7 relationship even with the 7 being way off.
> Depending on your definition of "tune". Regardless, pitch bends cover that if needed.
Pitch bend isn't a general solution unless you go all the way to one-note-per-channel like MPE does. MIDI 1.0 has no individual note pitch bend -- pitch bend affects all notes in a channel at once, which makes it quite a bit less useful for correcting intonation issues than it would otherwise be. (MIDI 2.0 added per note pitch bend.)
> All serviceable in the 12 note system.
According to your definition of "serviceable". Some of the people who actually practice these forms of music might have other ideas.
> If entire countries cede their musical theory systems for a foreign one it's not a matter of an accident, it's an indication of superiority.
Bad ideas can persist as well as good ideas -- 12-EDO wouldn't have survived as long as it had if it didn't have some useful characteristics, but I think it's important to be aware that 12-EDO is a compromise. Tuning suffers, but you can play equally well in any key, instruments are simpler when you only have to care about 12 notes per octave, and 12-EDO instruments play together.
With electronic music, the barriers to using other tuning systems are largely conceptual. Instruments could have as many notes per octave as you want, you could transpose freely while staying in precise just intonation, and tuning instruments to each other is just changing a number in memory somewhere -- much easier than retuning, say, a piano. So maybe the old tradeoff isn't a good one anymore, and we can make a better one. Or at least make it easy for people to choose what tradeoffs they want to make rather than having their choices made for them.
> Yes there is, it's exactly because near 100% of their users want just that. Most midi devices don't use anything past velocity and pitch bends, complicating them to include non-12 note systems would be a total flop.
I will grant you that 12-EDO is commercially successful and that major music companies largely have no interest in microtonality. That is, however, a very different question than whether non-12-EDO music has artistic and cultural merit.
For what it's worth, I expect MIDI 2.0, which has some features that make it better suited to microtonal music than MIDI 1.0, to be a flop. The microtonal crowd is probably better served by MPE (as kludgy as it is, it does work reasonably well), and device manufactures seem to have absolutely no interest in supporting it. Maybe it's more popular for software synths?
Interestingly, modular synthesis uses a 1v/octave pitch standard that is agnostic of tuning system -- people are free to use whatever they like. That is as it should be. Most people stick with 12-EDO because that's what they're familiar with, but if you want to do something microtonal, the only roadblocks are the artificial limitations put into individual devices, and you can largely avoid those if it's a problem.