Appending a note to the tuplet text (using a scheme wrapper function)

Sometimes you might want to show the basic beat in the tuplet number text, i.e. 3:2 quarternote, were quarternote is really a note. The quick and dirty way is to manually set \override TupletNumber #'text = #(markup #:italic "3:2" #:fontsize -5 #:note "4" 1). However, then you'll have to change it as soon as you want to use a 4/6 tuplet.

The better way is to write your own function for #'text, which extracts the tuplet fraction from the tuplet object, formats the tuplet text using the internal function and then appends the note you want. In other words, we simply write a function, which wraps the internal formatter function and modified its result:

#(define-public ((tuplet-number::append-note-wrapper function note) grob)
  (let* ((txt (function grob)))
    (markup txt #:fontsize -5 #:note note UP)))

You simply pass the “normal” formatter function (i.e. tuplet-number::calc-fraction-text for “3:2” or tuplet-number::calc-denominator-text for “3”) and the duration of the note to append:

  \override TupletNumber #'text = #(tuplet-number::append-note-wrapper tuplet-number::calc-denominator-text "8")

\version "2.24.0"

%% http://lsr.di.unimi.it/LSR/Item?id=482

\paper { tagline = ##f }

% a formatter function, which is simply a wrapper around an existing 
% tuplet formatter function. It takes the value returned by the given
% function and appends a note of given length. 
#(define-public ((tuplet-number::append-note-wrapper function note) grob)
  (let ((txt (function grob)))
    (markup txt #:fontsize -5 #:note note UP)))
  
{
  % Tuplet text of the form:  2:3 quarternote; 
  % "2:3" is produced by tuplet-number::calc-fraction-text, we only append the quarter note
  \override TupletNumber.text = #(tuplet-number::append-note-wrapper tuplet-number::calc-fraction-text (ly:make-duration 2 0))
  \tuplet 3/2 {c'4 c' c'}
  \tuplet 3/2 {c' c' c'} 
  % Tuplet text of the form:  12:15 eighthnote, 2:3 eighthnote, etc.
  \override TupletNumber.text = #(tuplet-number::append-note-wrapper tuplet-number::calc-fraction-text (ly:make-duration 3 0))
  \tuplet 3/2 {c'8 c' c'}
  \tuplet 6/4 {c'4:8 c'4:8 c'4:8}
  \tuplet 3/2 {c'8 c'8 c'8}
  \tuplet 3/2 {c'4 c' c'}
  \tuplet 12/8 {c':16 c':16 c':16} 
  \break
  % Tuplet text of the form:  2 quarternote
  % We can use the same wrapper function, only that we now use 
  % calc-denominator-text, not the full calc-faction-text
  \override TupletNumber.text = #(tuplet-number::append-note-wrapper tuplet-number::calc-denominator-text (ly:make-duration 3 0))
  \tuplet 3/2 {c'8 c' c'}
  \tuplet 6/4 {c'4:8 c'4:8 c'4:8}
  \tuplet 3/2 {c'8 c'8 c'8}
  \tuplet 3/2 {c'4 c' c'}
  \tuplet 120/80 {c' c' c'}
}