\version "2.14.2"

#(define n-list '() )

%{ pitch-to-color modified: print black and generate messages %}

#(define (pitch-to-color pitch)
  (let* (( nn (ly:pitch-semitones pitch))
	 ( m '(0 0 0 ) ))

    (set! note-i (1+ note-i))
   (set! n-list (cons nn n-list ))
   (if (>= note-i count-notes)
    (begin
     (set! note-i 0 )
     (ly:message "Notes: ~a \n" (reverse n-list ))
     (set! n-list '() ) ))

   m ))

#(define (color-notehead grob)
  (pitch-to-color
    (ly:event-property (event-cause grob) 'pitch)))



%{Test piece. %}

\layout {
  \context {
    \Voice
    \override NoteHead #'color = #color-notehead
}}

piece = \relative c' {
  c4 d e f g a b c,, d f g a 
}


#(define count-notes 12)
#(define note-i 0)

\score { \piece}
\score { \piece}