\version "2.24.4"

#(define (make-simple-pitch-debugger)
  (lambda (context)
    (make-engraver
     (acknowledgers
      ((note-head-interface engraver grob source-event)
       (let ((ev (event-cause source-event)))
         (when (ly:stream-event? ev)
           (let ((pitch (ly:event-property ev 'pitch)))
             (when pitch
               (let ((midi (ly:pitch-semitones pitch)))
                 (ly:message "🎵 Found pitch: ~a → MIDI: ~a"
                             (ly:pitch-format pitch)
                             midi)))))))))))

\score {
  \new Staff {
    \new Voice \with {
      \consists #(make-simple-pitch-debugger)
    } {
      \clef treble \key c \major \time 4/4
      c'4 d'4 e'4 f'4 |
      g'4 a'4 g'2 |
    }
  }
}