%% Generated by lilypond-book.py
%% Options: [indent=0\mm,verbatim,doctitle,alt=[image of music],texidoc,line-width=160\mm]
\include "lilypond-book-preamble.ly"


% ****************************************************************
% Start cut-&-pastable-section
% ****************************************************************



\paper {
  #(define dump-extents #t)
  
  indent = 0\mm
  line-width = 160\mm
  force-assignment = #""
  line-width = #(- line-width (* mm  3.000000))
}

\layout {
  
}



% ****************************************************************
% ly snippet:
% ****************************************************************
\sourcefilename "coloring-notes-depending-on-their-pitch.ly"
\sourcefileline 0
%% Do not edit this file; it is auto-generated from input/new
%% This file is in the public domain.
\version "2.12.0"
\header {
  lsrtags = "pitches,editorial-annotations,really-cool"
  texidoc = "
It is possible to color note heads depending on their pitch and/or their names:
the function used in this example even makes it possible to distinguish enharmonics.
"
  doctitle = "Coloring notes depending on their pitch"
} % begin verbatim

%Association list of pitches to colors.
#(define color-mapping
  (list
    (cons (ly:make-pitch 0 0 0) (x11-color 'red))
    (cons (ly:make-pitch 0 0 1/2) (x11-color 'green))
    (cons (ly:make-pitch 0 1 -1/2) (x11-color 'green))
    (cons (ly:make-pitch 0 2 0) (x11-color 'red))
    (cons (ly:make-pitch 0 2 1/2) (x11-color 'green))
    (cons (ly:make-pitch 0 3 -1/2) (x11-color 'red))
    (cons (ly:make-pitch 0 3 0) (x11-color 'green))
    (cons (ly:make-pitch 0 4 1/2) (x11-color 'red))
    (cons (ly:make-pitch 0 5 0) (x11-color 'green))
    (cons (ly:make-pitch 0 5 -1/2) (x11-color 'red))
    (cons (ly:make-pitch 0 6 1/2) (x11-color 'red))
    (cons (ly:make-pitch 0 1 0) (x11-color 'blue))
    (cons (ly:make-pitch 0 3 1/2) (x11-color 'blue))
    (cons (ly:make-pitch 0 4 -1/2) (x11-color 'blue))
    (cons (ly:make-pitch 0 5 1/2) (x11-color 'blue))
    (cons (ly:make-pitch 0 6 -1/2) (x11-color 'blue))
    ))

%Compare pitch and alteration (not octave).
#(define (pitch-equals? p1 p2)
  (and
    (= (ly:pitch-alteration p1) (ly:pitch-alteration p2))
    (= (ly:pitch-notename p1) (ly:pitch-notename p2))))

#(define (pitch-to-color pitch)
  (let ((color (assoc pitch color-mapping pitch-equals?)))
    (if color
      (cdr color))))

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

\score {
  \new Staff \relative c' {
    \override NoteHead #'color = #color-notehead
    c8 b d dis ees f g aes
  }
}



% ****************************************************************
% end ly snippet
% ****************************************************************