Can't transpose in a microtonal system


I think there’s something I don’t understand about the transpose dialog when I’m using a non-12 EDO system.
I cannot select any different value than an octave in the dialog.
All the alterations, except the Natural, are nameless in the calculator, even if they have names in my 1200 EDO tonality system definition.
In the dropdown dialog of the divisions to transpose, I only have +0/1200. There’s no option to enter any other value.

What am I missing here?

Captura de ecrã 2018-12-27, às 23.45.06.png

If you change the interval from ‘Unison’ to e.g. 2nd or 3rd, you should find that the ‘No. divisions’ list then shows the valid possible numbers of divisions.

OK, I can see now that I can have a 2nd, 3rd and 4th for upward intervals. I can understand that some of my alterations are not possible to transpose (I’ve used 6ths of a whole tone with approximations of 33 and 66) but for half-tones and the alterations I have defined, it should be possible to transpose any of those. Why don’t they show up as possible options?
In a 1200 EDO system I can only have +200, +500 and +700 upwards, and -500, -700 and -1000 downwards.

Dorico will not only determine which divisions are applicable for the selected interval, but it also examines the actual musical content to determine which intervals are valid, and will not allow you to choose a combination that would produce any non-notatable notes.

…because Dorico is amazing. :laughing:

Ah, I didn’t realize the exclusion technique the transpose dialogue uses. Pretty interesting.

Still, there’s something awry with things, given the options I can see (attached, 6.png). I’m on a 224EDO, so it doesn’t make sense to me that 225EDO stuff is popping up. I did at one point have a 225EDO due to a typo in the tonality system setup, but that’s no longer the case; at least, I don’t think so. I’m surprised that number popped up.

The two notes I selected for this transpose test are, in fact, transposable, so at least there’s that. Lots more strange interval options pop up when I select a single note (attached, 7.png).

I think I’d need to see the project in question to say for sure, but I guess that perhaps one of the accidentals in your tonality system is set up with a different number of divisions?

Ah, good idea to check that. I found a couple of accidentals that still had xx/225 instead of xx/224.

Still, it doesn’t really make sense to have those left in there once the divisions is set to 224, that they don’t update automatically.

Well, how would you like it to change them when the denominator changes? Imagine you were changing from (say) 144 to 96. How would you want it to round the numerator to fit the new denominator?

When you’re working with these kinds of precise tonality systems, Dorico does its best to get out of your way and allow you to manage it yourself. This also means that you are given sufficient rope to hang yourself, of course.

I think the numerator shouldn’t change at all until the user does it. A hypothetical accidental of 10/144 should become 10/96.

That would actually change the ratio, whereas the current system leaves the accidental as defined. There could be the option to transform it manually to the current EDO, whether exactly or rounding, but changing just the denominator makes it a whole different accidental.

Of course. When you would want to actually not change the ratio if you change the EDO? For example, going from 12EDO to 13EDO without altering sharps or flats gives you a bunch of accidentals that are still in 12EDO if the ratio does not change, meaning you don’t actually get 13EDO until you manually change those accidentals anyway. Then, as soon as you edit one of your old 12EDO accidentals, it gets saved as 13EDO and you can’t switch it back to 12EDO without redefined your scale again. Who would actually want this behavior?

This behaviour is desirable if, for instance, you want to switch from, say, a 12EDO to a 24EDO, without having to alter all the music itself.
Or, for instance, in my case, I had a project where I used a 1200EDO system (cents). I used a lot of 6ths of a tone (33 cents), and in the end I realised that it was better to use a 720 EDO system, to have exact 6ths of a tone. This solved a lot of my transposing problems that I had when I opened this thread.
However, when I made the transition, since 33/1200 and 20/720 are almost but not exactly the same, there was no direct correlation. In my case, it was useful to keep the original ratio until I updated all the alterations.
If you switch from 12 to 13 EDO, since there’s no direct conversion from any division other than the octave and the other, you have to define manually the equivalence of the alterations you defined.

However, there could be an easy way to update the alterations manually, either by equivalence or approximation (33/1200 to 20/720 for instance) or by updating just the denominator (as you say, 1/12 to 1/13). However, since both scenarios are possible, the option should be given to the user.

Ah, I never thought of doing things like that, but I find what you describe here can make sense. Thanks.

Food for thought: what you describe here is translating between tonality systems. As you say, perhaps some tools to facilitate altering already written music between tonality systems can be added. Not just for this specific case of getting multiple denominators in the accidental definitions, but also for completely differently defined systems - for example, between 1200EDO and 720EDO or 12EDO and 13EDO.

One function that may be helpful here is simply a way to change only one pitch of a given selection of measures. Thus, if a user decides one note works better in some other tonality system than originally intended, they could maybe select 50 measures and with this function force all the instances of that one note in that selection to their desired new note. Functionally, this is different than the ‘transpose’ function; it’s more like the ‘find and replace’ from MS Word.