Re: Add Modal transformations (issue4126042)

[Trevor Daniels]

Graham Percival wrote Wednesday, February 02, 2011 7:38 PM


> IIRC, "diatonic" can refer to any church mode.
>
> Let me rephrase / alter my initial suggestion: might it be worth
> having some predefined scales for actually well-defined scales?
> Like \major or \locrian or the like?  They could go in a new
> ly/*-init.ly file, or maybe something in scm/.  Something like
> "define-scales-init.ly" ?

Well, we could, but each scale would be specific to a single
key.  We could choose to define \major in the key of C and
expect users to use \transpose to generate scales in other
keys, but as Keith pointed out that is hardly shorter than
writing out the desired scale anyway.  And what key would you
chose for \minor?  Am or Cm?  And to distinguish the several
minor scales the names would need to be longer still.

The scales of the various "church" modes appear to have several
variants, apart from being key-specific, although I confess to
being pretty ignorant here.

For pentatonic scales there are even more in common use,
I believe.  Even the five black-key scales are all distinct.

> For octatonic, we could have octatonicA and octatonicB, or
> something like that... IIRC there's only two types of those
> scales.  (or maybe we should avoid using A and B, and instead call
> them "octatonicBeginFull" and "octatonicBeginHalf" ? )

These are modes within any one of the three distinct diminished
octotonic scales.  But in total there are 42 other 
non-enharmonically
equivalent octotonic scales.

So I wonder if this is worth the trouble.  AFAIK there is no
universal naming convention to distinguish them all.  As
Bernard says, he is engaged in systematically naming all the
seven-note scales, and even this is with limitations.

Trevor