Chord Types are named collections of intervals. For instance, a major chord (M) is a collection of the I, III, and V intervals. You can specify the intervals in a chord by using the very powerful Tone Spiral.
Even though conventional chords can look pretty complicated, like FMaj9+11/C , PolyHarp has so many kinds of intervals, and no restrictions on which shall be collected with which, that you need some creativity coming up with chord type names. For example, you could have a chord that is 1/1, 5/4, 34:51, 9:5@5/4, 115.3434 (cents) and so on. These chord types are then used with transposition interval to specify a Chord_bar.
A lot of chords built with different intervals function in similar ways - the aforementioned M (Major third), made of I-III-V works a lot like its just cousins 1/1-5/4-3/2 or the 19-EDO 0:19-6:19-11:19. It'd be interesting to set up "namespaces" so that the names of the chords match how they function more than how they are technically constructed - which you could discover if you could find its namespace. You can use the "tags" feature of the chord types to help with that. Also, you can give a chord type a name with a " " (space) in it, and it can peel off what's in front of the " " when it names the chord button, so it doesn't have a long name!
At any rate, I am hammering out a few PolyHarp-only chord naming conventions to help out somewhat.
The Chord Type name and Description are pretty self explanatory, and the tags are covered a little below, but there is also the repeat interval.
A chord type can either repeat within its repeat interval or exactly specify which intervals make it up. This helps in most situations, since you'd normally specify an octave's worth of intervals and transpose them by an octave up and down the scale. But there are exceptions! For example, to make a 31-EDO scale, all you'd have to do is specify a 1/1 , select "repeat", and make the repeat interval 1:31. You can make scales that repeat at all kinds of intervals, or not at all. Non repeating scales are useful for precisely setting intervals on specific strings.
Each string that a chord type creates is normally placed where its pitch would normally place it, as if it were on a piano keyboard. That is, it is logorithmic with respect to octaves. But sometimes, you want to move that string, or reuse it with several piches. For that, there's a separate interval spec available called the "On_String" spec. This is like how, on a guitar, you can play a C on an A string. In PolyHarp's case, since you don't know the exact tuning of each string (kind of like using a capo...), you'd have to specify the string position using the interval of where the string ought to be. This way, different notes can be played on the same string (like a guitar). In a weirdly expanded way, you can build fretted chords and strum them.
Sometimes, I just set that up as equally divided intervals, like 0:6, 1:6, 2:6, etc. for a 6-stringed instrument, but you can bunch them up more and also put them in reverse order.
The On String string's location is as if 1/1 (0 cents) is based on C4.
As another consequence, you can make one of these retuning scales, repeat it, and add create a lock bar chord based on this scale (transposed by the chord interval). The effect is to retune the strings in all the chords that use those strings (and of course damp the strings that aren't in the lock bar).
You can swap the tone spiral's display from showing the Interval to the On String Interval by touching the name "Interval" or "On String". An unset On String just uses the interval to position the string.
The Tone Spiral is a way to visualize intervals. Each whorl is a new octave, and intervals are laid out on the tone spiral as big white spots.
Add a new interval with the (+) button. it will be places in the middle, inused portion of the spiral. You can then drag it to a place you'd like it to be.
Similarly, you can remove an interval with the (-) button
There are buttons to build guides that you can snap to:
Using the Tone Spiral button,
If you are looking at On_String intervals, it creates them with on string Intervals as well. After that, you can go back to looking at Intervals and "retune the strings".
You can use the Free and Snap buttons to either perturb your intervals a little or make sure they snap to the guides.
You can also just directly type in an interval that you have selected. You can select an interval by clicking on it, or, if they are too dense, by using the << and >> buttons.