Re: ly:pitch-alteration

[Hans Åberg]

> On 21 Jul 2020, at 05:08, Freeman Gilmore <freeman.gilmore@gmail.com> wrote:
> 
> This is where I got ly:pitch-alteration. from, but I do not know how
> to use it:
> http://x31eq.com/lilypond/

This is Graham Breed, you might check out some of his posts here on the 
LilyPond lists.

> The Pitch Model
> 
> Pitches in Lilypond are a combination of the position on the staff,
> and the alteration relative to the nominal at that position, as a
> rational fraction of a 200 cent whole tone. Pitch names repeat every
> 1200 cent octave. You can create a pitch with ly:make-pitch and find
> out about an existing pitch with ly:pitch-octave, ly:pitch-notename,
> and            ly:pitch-alteration.            There's also
> ly:pitch-steps, which is a combination of ly:pitch-octave and
> ly:pitch-notename, and ly:pitch-semitones which can be risky in a
> microtonal context.

It is very complicated to use. You might try the regular.ly file which allows 
for ETs in the MIDI output. I can send you some examples for some of them, like 
E53. Graham has made a file that allows for more complicated microtonality, by 
using a high ET so that the microtones do not clash.