How could you go microtonal?


#1

I don’t really know much PD, but I’ve recently gotten into listening to some microtonal music and would like to find a way to use the Organelle to play custom scales. Kind of an easy answer would be to tune samples on a computer and just play them on the Organelle, but I feel like that takes some of the fun out of it, and seems tedious if I want to switch between scales or sounds. Anyone have any advice/ideas, or know of any patches that already exist like this? It seems totally doable, but I’m not sure the most efficient way to approach it.

And slightly tangential to that, anyone know of any good way to send microtonal notes to a synth? There’s a way to send it by pitch bend cc, it’s only mono though and according to some people not very accurate (I honestly don’t know one way or the other). It would probably work best via modular, right? (audio to cv?)


#2

this is actually pretty simple :slight_smile:

within the organelle pure data patches both midi and the organelle keyboard notes key converted to a send called notes , which are received with [r notes]
so this note is a midi note, so notionally its an integer, but it is interpreted as a float, a fraction - so 60.5 is valid - this is then usually converted to a frequency using [mtof]

so:
a) there is a mapping from a fractional note to the frequency often by mtof
b) fractional notes are fine

this means there are two ways to do microtonal mapping

a) your micro mapping goes from notes to frequency, so replaces mtof
this means going thru every patch, at replacing mtof with your own microtonal mapper
i.e [r notes] -> [mtof]-> [oscillator], becomes [r notes] -> [micromap] -> [oscillator]

b) your micromap goes from notes to notes, just rescaling etc.
this is actually probably the better approach.
basically take the midi note, and remap them to your microtonal scale.
i.e. [r notes] -> [micromap] -> [s notes] (this wont work but is the idea :wink: )

the great thing about this approach is
for normal patches you can do this in mother.pd, so without touching the patch code!
for orac, you could create a midifx module, which does it … so would work for all synth modules, and even work with sequencers etc :slight_smile:

of course for bonus points, create an orac module that interprets scala files and uses these as the mapping.

this is the ‘same issue’ as expressive controllers, and so the approach is the same…
you indeed use pitchbend, but you would put each note on a separate midi channel.
this of course, requires that your synth is MPE aware… though you can do it with a multtimbral synth by loading the same patch on multiple channels.

inaccurate - done know who told you that, they are talking nonsense;)
PB is 14 bit, so there is plenty of resolution for microtonal , as that 8192 steps per semitone
(for expressive controller its less than that, since we want to slide over at least a couple of octaves, but even that is absolutely fine!)

modular, it would really be audio as such, it would have to be DC coupled.
and then it depends on the resolution of the DAC, but it probably be 24 or 32 bit, so a bit higher…
the main thing about modular though, is it not midi focused, CV pitch is just voltage, so (except midi modules), things like oscillators are assuming continuous voltage not ‘steps’.
but its expensive to start building a polyphonic modular, microtonal or not :wink:
so… not really better, just different.


#3

“Resample” can be fun! with assistance :wink:


#4

Thanks Technobear for the in depth answer!
That all makes sense (or at least sense enough for me to start tinkering around). It sounds like an orac module that could interpret scala or .tun files would be perfect, because that would make it easier to try different tunings using different sounds, but that sounds like more advanced programming than I would be able to do at the moment so I’ll leave that as a long term goal.
I also should have been more clear on my modular question, I didn’t explain my set up or thought process at all. This is all for recording/studio purposes, but so far I’ve only been able to find some software for making microtonal music but no way to send it out to any synths I already have (Minilogue, 0 coast, Dark Energy). I figured CV would make more sense (even if it’s only mono for now), but I’m not sure how to best use midi to CV for microtonal. I figure the Organelle might be a good start, it can generate microtonal tones, but using that to control other pieces of gear is where I’m a little lost. I know there are a lot of ways to approach something like this, but I’m not sure what would yield the best and most straight forward results, that hopefully wouldn’t involve buying anything.

Keymanpal, that’s an awesome application! Looks super useful in general and could help setting up a microtonal rig, thanks.


#5

I posted a version of the ‘1008’ patch that has some microtunings built in here:


I’ve also been playing around with some microtonal modules in orac recently.
Great idea on a standalone midifx module @thetechnobear, I didn’t think polyphonic patches would work with fractional note inputs but they seem to work fine.
I just took out the microtuning subpatch I’ve been using and put it in a standalone module. It doesn’t support scala, but it has 18 different tuning systems, you can download it here:
https://github.com/adbrant/orac_dev/raw/master/pkg/U-micro.zop