Re: Adding a root note next to the key signature (like a single note Ambitus)

[Lukas-Fabian Moser]

Am 05.07.22 um 23:39 schrieb Lukas-Fabian Moser:

Hi Viktor,

Am 05.07.22 um 20:17 schrieb Viktor Mastoridis:

For educational purposes, I would like to see whether it's possible to add a small note head after the key signature?
Like a single Ambitus note, really.


Why would I do it?
For example, I would like to add a (small) D note to a G-Major key signature, suggesting that, despite the F# key indicating G-major or E-minor scale, this piece is in D-Myxolydian mode.

Maybe something like this?

... probably cleaner not to re-define key, but record the current tonic in the KeySignature grob using an engraver.

    \version "2.23.10"
    
    tonic_notehead_engraver = #
    (lambda (ctx)
      (make-engraver
       (acknowledgers
        ((key-signature-interface engraver grob source-engraver)
         (if (eq? (grob::name grob) 'KeySignature)
             (ly:grob-set-nested-property!
              grob '(details tonic) (ly:context-property ctx
    'tonic)))))))
    
    notehead_key_signature = #
    (lambda (grob)
      (let*
       ((key-sig (ly:key-signature-interface::print grob))
         (notehead
          (grob-interpret-markup grob
                                 (markup #:tiny #:musicglyph
    "noteheads.s2")))
         (notehead-parens (parenthesize-stencil notehead 0.1 0.3 0 0.1))
         (tonic (assq-ref (ly:grob-property grob 'details) 'tonic))
         (tonic-position (+ (ly:pitch-steps tonic)
                            (ly:grob-property grob 'c0-position)))
         (adjusted-tonic-position
          (- (modulo (+ tonic-position 3) 7) 3)))
    
       (ly:stencil-combine-at-edge
        key-sig X RIGHT
        (ly:stencil-translate-axis notehead-parens
                                   (/ adjusted-tonic-position 2) Y)
        0.5)))
    
    
    \layout {
      \context {
        \Staff
        \consists #tonic_notehead_engraver
        \override KeySignature.stencil = #notehead_key_signature
      }
    }
    
    {
      \key d \mixolydian
      a'1
      \key a \mixolydian
      1
      \key g \mixolydian
      1
      \key g \dorian
      1
      \key c \minor
      1
      \clef bass
      d1
      \break
      1
    }