Re: 48 and 72 ET

[Graham Breed]

I'm answering the whole thread here.

You should be able to do 48 ET with the standard Lilypond font.  You 
can, for example, start with 12 ET and add arrowed accidentals to get 
12*3=36.  Then add 12 quartertones to get 48 ET.  All you need is to 
define new note names.

I found the font wasn't good enough for 72 ET, and I don't think that's 
changed.  Which is a shame, because it should be easy for somebody 
familiar with Lilypond's font workflow to add the arrows to quartertone 
symbols and that's all you need to get 72 (24*3).  I did find enough 
symbols for 60-ET and I use 60 and 72 as output formats for tripod 
notation as it happens.  From what I remember, there are a lot of flat 
symbols that can be interpreted in different ways, but not so many sharps.

It would be nice for regular.ly to be included in the standard 
distribution, but that's irrelevant here.  What regular.ly does is 
retune the note names for a different size of fifth.  48 and 72 ET keep 
the same fifth as 12 ET.  What you need is a new "language" for the note 
names and appropriate glyphs.

I have files to support arbitrary fonts but there are issues with the 
spacing.  I have an experimental branch for Extended Helmholtz-Ellis JI 
Pitch Notation with Bravura but it doesn't solve any problems with the 
dedicated HE font.  (This is the "eheji" branch in the microlily 
repository.)  This particular notation always needs "text" fonts because 
it builds glyphs into strings to make the accidentals.  The standard 
accidental code only uses one glyph at a time which is good enough for 
72 but not Helmholtz-Ellis.  Still, having Bravura blessed as a Lilypond 
font would be both a good thing and quite a bit of work.

It's unfortunate that my library is out of date.  It's good that 
convert-ly fixes it.  One issue with this is that libraries (at least 
the way I use them, which may also be out of date) don't declare the 
Lilypond version.  It's in the including score file and if the included 
file also declares a version there is (or was) an error.

Anybody can fork the repository and keep it up do date.  I can add the 
license of your choice if you care about such things.


                Graham