### making a 50 cent tuning system

I want to make a midi implementation of a quart tone system, based on the following expression that is the abstraction of mtof

expr (440. * exp(.057762265 * ($f1 – 69.)))

I am not very good at maths, so what I want to do is to divide an octave in 24 parts.. for an instance, instead of having relations like c, c#, d, I want to have c – C#1 – c#2 – d

where c#1 c#2 are quart tones

This equation will do what you’re looking for. It uses MIDI note value 69=440Hz and works in quarter tones from there.

lh

**all**of the following text. Then, in Max, select

*New From Clipboard*.

```
----------begin_max5_patcher----------
411.3ocwU00aCBBE8Y8WAgrGzEqqRo5buseGqMK9AskEELJl5VS+uOA0ztkz
HYy19BDtb4bOb3dubvz.FyaHUPvKf2.FFGLMLTljFL5Wa.yiZRxhpTtA2jwY
04PmtsJhDI6nrsuWRRDcvrLzctCvyGKmVNWNhZGAq6OxFNSvhxIJzdsjFkM.
VKtTVFQnBj2Ii7ZwfUzYfTQ+RAhGpMFclooJT4weLyye.1tiK9rfzQP4UHR.
c.v3H1VHXszsillxAGMUAFYeaPFhffzH5DGAOGL2cb0AK4L.GLspim9pC5hp
yeSPzMs.oRHBWbuRKBupYE04wjxQEg.+6aowkqLnrqScAiKHT1nByRUOCr+z
JLKzVXviILmMMkxCoonDXUv2agbWsxwx5gMdy7CcseBgcssseDi0noR3ypJr
ot1R+lJAZ1SQwKXFk86edTWMo8eJgU75xjAn5em.mtcojJAkEInb1Y93+Ce1
QSSIpsG3cNMsf29P1SgK7bpKi70fQA2TFI6vOJk7tspTnNTBcSoTfFTJ7evn
1EGM+F.8foRK
-----------end_max5_patcher-----------
```

i know that it does.. the only thing i don’t know is which float number to use to make the conversion to a quarter tones (50 cents relation) instead of 100 cents relations

Apologies, I meant the equation I included in the compressed max file posted underneath. To view it, highlight all the text including the —— bits at the beginning and end, copy, then open a new max document and paste it in. If you use max 4 then it won’t work, but the equation is:

[expr (pow(2.,(($f1-69.)/24.)))*440.]

where the value "24" is how many divisions you want per octave. If this value was 12 the equation would behave exactly as the standard [mtof] object does. It is another way of writing the equation you had in your first post.

lh

[gangsta~]

On 23 Dec 2008, at 18:07, Mike S wrote:

> [gangsta~]

You beat me to it.

All the attribute names seem to start with the word "bling."

Innit?

– N.

Nick Rothwell / Cassiel.com Limited

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