Re: Extracting a "score diff" from two [or more] Lilypond sources

[Kieren MacMillan]

p.s. Motivating use case:

I'm cranking out scores for my newest musical 
(https://www.ccpacanada.com/the-quest/). Rehearsals started on Tuesday, and 
changes always come fast and furious during the workshopping of a brand new 
piece. Every time I send the Musical Director an updated score, I would love to 
not have to list all the changes (I'm not yet rich or famous enough to have a 
music assistant to do that kind of grunt work!), so I'd love to just pass two 
scores through a "Music AI" and include that output with the new score.

— Kieren

> On Jan 22, 2022, at 4:51 PM, Kieren MacMillan <kieren@kierenmacmillan.info> 
> wrote:
> 
> Hi all!
> 
> Given multiple Lilypond sources, I'm hoping to find a way to output a "diff 
> file" describing the musical differences *as would be perceived by a human 
> reading the score*. For example, given
> 
>    Score #1 = \score { \new Staff << { c'1 c' } >> }
> 
>    Score # 2 = \score { \new Staff \new Voice << { c'1*1/2 s2 c''1 } >> }
> 
> diff ( Score1 , Score2 ) would say [in effect] "m2: Score #1 has c'1 while 
> Score #2 has c''1."
> 
> Because coding style, "hacks" (like c'1*1/2 s2), variable/context separation, 
> and other code-based differences aren't [directly] relevant, I can't just use 
> standard text/diff tools. Is there a way two "music streams" (oof, I'm 
> definitely talking out my butt right now!) can be compared in Lilypond and 
> some/most/all of the human-perceivable musical differences be automatically 
> detected?
> 
> Thanks for any brainstorms, ideas, or (dare I dream!?) snippets!
> Kieren.