[PD] making scales from frequency values

Derek Holzer derek at umatic.nl
Tue Jul 21 00:31:04 CEST 2009

Unlike all the rest of the equal-tempered scale, octaves are easy, just
divide by half or multiply by two (or multiples thereof). If it's thirds
and fifths and all that, it gets a bit more complicated unless you are
into just intonation where the ratios are actually the ratios and
haven't been "t(a/e)mpered" with (by setting up logarithmic
relationships inside the octave rather than across the whole range of
notes.)

http://en.wikipedia.org/wiki/Mathematics_of_musical_scales
http://en.wikipedia.org/wiki/List_of_meantone_intervals
http://en.wikipedia.org/wiki/Just_intonation

For myself, using the just intonation ratios just works because it's
simpler math. However, like Andrew I'm not sure beyond this simple
advice what it is you're exactly trying to do. So hope this helps... Any
actual lettered students of tuning systems feel free to kick me, I'm a
mere dilettante in this world...

best!
D.

J bz wrote:
> Dear all,
>
> I have five chimes.  I've worked out the frequencies (using Audacity) of
> the 5 strongest partials of each chime.  I now want to be able to work
> out how to change the octaves of the various partials?  My original
> intention was to find the nearest midinote and just use those but after
> listening to the results I would much prefer to keep the original
> ratio's whilst being able to alter the 'inversions'.
>
> Here's the list that I have already:
> BT1
>     912Hz
>   2434Hz
>   4575Hz
>   7175Hz
> 11584Hz
>
> BT2
>   1081Hz
>   2861Hz
>   5339Hz
>   8325Hz
> 15209Hz
>
> BT3
>   1211Hz
>   3196Hz
>   5935Hz
>   9199Hz
> 15206Hz
>
> BT4
>   1347Hz
>   3553Hz
>   6569Hz
> 10128Hz
> 18139Hz
>
> BT5
>   1812Hz
>   4699Hz
>   8525Hz
> 13264Hz
> 15469Hz
>
> Is there one piece of mathematrical wizardy that can sort this in Pd?
>
> Cheers,
>
> Jbz
>
>
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--
::: derek holzer ::: http://blog.myspace.com/macumbista :::
http://www.vimeo.com/macumbista :::
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