What is the smallest difference from equal temperament that you find acceptable for nice chords?
When fine tuning a harmonica, one faces the decision of whether one wants to prioritise melody playing in many keys or nice, pure-sounding chords in one key. In the former case, one tries to approximate just intonation, i.e. the exact pitch displayed on most tuners where every interval of a certain type is the same, while in the latter case one chooses some kind of just intonation where the some intervals are made smaller or larger to make the ratios of the frequencies match certain fractions.
One could go for either of these extremes or try to find some compromise in between them, and the choice is rather subjective.
The reason I ask is that I have been tinkering with tunings with chords from many different keys. I could have them all conform to just intonation, but in some places that would mean that the deviations from equal temperament would add up and become rather large.
For example, a just minor third could be as much as 16 cents sharper than an equally tempered minor third. If we stack three just minor thirds on top of each other, like A-C-Eb-Gb, the difference in intonation between the first and the last note will be 3*16=48 cents, which means one side of the harmonica will be badly out of tune with the other.
On one of Pat Missin's pages, (https://www.patmissin.com/tunings/tun9.html) he suggests that a deviation as small as 5 cents might be a reasonable compromise. He also has some good samples that show the difference between just, compromised and equally tempered chords.
Personally, I'm inclined to forgo the sweeter sounding just chords to get a construction that works in many keys without having to retune other instruments between key changes. I can hear the difference between a just chord and an almost equally tempered one, but in a context with several other instruments I'm not overly bothered by it.
But it makes me curious about how you all think about these things!
How do you tune your chords? Do you even use different compromises for different situations? Have you changed your mind about intonation?
I know intonation is a common topic among people who play standard tuned harps, but they only have 2-3 chords to worry about. Any thoughts on intonation of chords in alternate tunings would be particularly of interest, but experience from the Richter side of the aisle is welcome as well
