Re: function to force accidentals on a subset of notes

[Michael Winter]

Thanks Lukas!

This works but also forces the accidental on tied notes.

Best,

Michael

Oct 22, 2023, 10:19 by lfm@gmx.de:

Hi Michael,

this is easily accomplished with an custom engraver. (I perfectly understand that the terms "easily" and "custom engraver" don't seem to go well together at first - I thought so for many years as well -, but after some getting used to it, the concept is actually quite simple and elegant.)

\version "2.24.0"

forced-accidentals-pitches =

#(music-pitches #{ bes b #})

#(define (diatonic-pitch-class= p q)

   (and (= (ly:pitch-notename p) (ly:pitch-notename q))

        (= (ly:pitch-alteration p) (ly:pitch-alteration q))))

Force_accidentals_engraver =

#(lambda (context)

   (make-engraver

    (listeners

     ((note-event engraver event)

      (if (member (ly:event-property event 'pitch)

                  forced-accidentals-pitches

                  diatonic-pitch-class=)

          (ly:event-set-property! event 'force-accidental #t))))))

\layout {

  \context {

    \Voice

    \consists #Force_accidentals_engraver

  }

}

\transpose a c' \relative

{

  a8 gis g fis g gis a4

}

Lukas

Am 21.10.23 um 11:37 schrieb Michael Winter via LilyPond user discussion:

Thanks Jean,

I am not sure I completely follow.

Lets say I have a music sequence:

a b c d e f g a bes c d e f g ...

How do I apply what you have written as a function to only show the flats and naturals for b and bes. Again. I do not want to apply this to individual notes.

Sorry if I am missing something.

Best,

Michael

Oct 21, 2023, 01:37 by jean@abou-samra.fr:

Try

\displayMusic c'!

This shows you that the ! syntax corresponds to setting the force-accidental property to true. Thus, if you have identified the note events you want to force accidentals on, you can do

(ly:music-set-property! the-note-event 'force-accidental #t)

on each of them.

Best,

Jean