Re: Diatonic/modal transposition function

[Graham Breed]

2008/12/29 John Mandereau <address@hidden>:

> This work is not synced at all with Graham's work, but it tries not to
> naively assume any temperament; in current state it only works with
> 7-notes scales, but the arithmetics on alteration works with any kind
> alteration, semi-tones or microtonal alterations.

Right, that's how it looked to me.  If it doesn't assume equal
temperament it should work generally.  But I haven't tested it.

Note that I discovered it is possible to get more than 7 scale steps
to the octave (see the development list).  So this would probably
generalize accordingly.  But I don't know if anybody's ever going to
make the (AFAIK global) change of scale size and then want to do modal
transpositions.  If they do they can hack your code.

> BTW I'm sure it is feasible to extend these transposition functions to
> scales with other lengths assuming equal semi-tones temperament (E12)
> (e.g. for Messiaen's modes), but I'm not knowledgeable enough about
> scales and modes definitions you discussed with Graham on -devel to tell
> how the functions I wrote should be extended to support these scales.

I know there's a snippet in the documentation for chromatic
transposition -- and maybe that's where you started from.  7 note
scales are the next most important application, anyway.


                            Graham