Determining Number of Notes in Scale

I am looking for a way to count the number of notes in a scale (in one octave). I have a patch that uses Oh Peas by @computerscare and I want to take full advantage of its built-in scale options, but I am using interval-based inputs similar to the Eventide Misha and the intervals are different in different scales (i.e. a pentatonic scale has 5 notes, a blues scale has 6, and a major scale has 7 notes per octave).

Here’s what I have now:

The Goly Penerator sends 12 equally spaced signals between 0 and 1 volt through Oh Peas. Oh Peas quantizes to the set scale, then the signal is split and sent to comparators. The first compares channels 1&2, the second 3&4, and so on until the last which compares 12&1 to get the extra needed signal for the root note to count. This image is a pentatonic scale, so five “not equal” signals send out 10v each. Those are summed then divided by 10 to get 5v which I can then use in the patch to set interval voltages. When I set Oh Peas to major or minor, I output on the far right changes to 7v.

My current solution works, but I am sure I am just missing the perfect module or search term to find the perfect module. Anyone have a better way to count notes than this?

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Pretty cool solution, could you explain what is happening later in the patch and how you are using the “number of notes” voltage signal?

Sure! Here’s a bit more context:

I’m sending the “number of notes” signal (7v in this image) to 8 different AO-101s that are dividing constants by that signal to set the step amounts on the Accumulators. This turns the bottom row of my keyboard into a boring version of those cool flying V interval buttons on the Eventide Misha.

Excellent work, by the way! I love these modules. I am just getting to know Oh Peas and it truly rules. Thanks for the kind words and any help you can offer!

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I’ll admit, I still don’t really understand but seems like a cool project! As far as how to simplify, my first thought would be to skip the calculation and use a Stoermelder 8Face to save a number of presets of Oh Peas. You could keep the “number of notes” as the offset value of one of the unused Oh Peas channels, then you would be sure it’s always exactly whatever you desire for the particular quantization scale. Not as fun as doing it modular… but would save some space and potentially be more reliable.

Glad you enjoy the computerscare modules, thanks for the kind words!

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I think you can still reduce the size of the note counter by feeding the quantized output of Oh Peas into the Note Classifier module from Sparkette’s Stuff, and sum the outputs of it using Sum from docB.

Like this:

I’m also a big fan of Oh Peas, as it is one of the few quantizers available that does quantization correctly, by assigning the notes in an “equi-likely” way (Quant from Grande is another one).


This is perfect! I knew there had to be an easier way to determine how many notes are active. You should have seen the ridiculous flip/flop binary counting logic system I had in a pervious patch before @DaveVenom told me about Accumulator. Once again, @docB comes through with the space saving utility I need. Thanks for the help!

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For anyone looking for a VCV Rack Misha emulator, I’ve got the single-note mode sorted out and chord mode is working for most of the scale presets. I’d love some help figuring out a couple snags and optimizing this patch. Here’s what I have right now.

Hi Riley.

I downloaded your patch and added an FM-OP local voice so I did not have to have a VST voice and it was working okay, at least it seemed to be.

A month or two ago I did a Misha emulation using my Meander module and octal radix voltages to control chords and melodies, but not at the same time. But If I controlled Meander’s chords, Meander could do the accompaniment for melody and bass. I also used BASICally for the scripting.

Looking at your patch though, I think it is too complex for me to work through to understand what is working, what is not working and how to make what is not working work.

It is a complex problem.

I think it is cool however that you have taken this as far as you have. Maybe someone else is better at untangling very complex patches and understanding them.

Best of luck.

Here is my post and patch for the above: Purr Software's Meander Module - #609 by k-chaffin