Mats-Olof Liljegren:
...
> What I want to do is create an override or an extension that
> changes only the parts I need to modify, while keeping the
> rest intact. I assume this is possible, but I havenât
> understood how.
...
Not exactly as you request, but did you try Lukas_Fabian Mosers suggestion
(Sun, 20 Apr 2025 16:34:35)? It was something like:
Put this in file svinglish.ly:
> cut
\version "2.24"
#(define svinglish-note-names
  `((cessess . ,(ly:make-pitch -1 0 DOUBLE-FLAT))
    (cesseh . ,(ly:make-pitch -1 0 THREE-Q-FLAT))
[ etc ]
    (bississ . ,(ly:make-pitch -1 6 DOUBLE-SHARP))
    (bississ . ,(ly:make-pitch -1 6 DOUBLE-SHARP))
    ))
#(set! language-pitch-names
      (cons (cons 'svinglish svinglish-note-names)
            language-pitch-names))
> cut
And then in your lilypond file:
\include "svinglish.ly"
\language svinglish
\relative {
 c'4 d e f g a b c
}
I haven't tested this but please report back if it works, if not
consult his mail.
If it works you can can keep svinglish.ly alongside your other
lilypond files.
Regards,
/Karl Hammar
