Bass buttons on my brother's accordion

gistfile1.rb

module Accordion
  TONES = ['C ', 'C#', 'D ', 'D#', 'E ', 'F ', 'F#', 'G ', 'G#', 'A ', 'A#', 'B ']

  def get_tone t
    TONES[t%12]
  end

  def rel tone, dist
    get_tone((TONES.find_index(tone) + dist) % 12)
  end

  def line tone
    [8,4,0].collect {|i| rel tone, i}
  end
end

include Accordion

def pline a
  a.each { |i| print "#{i}  "}
  print "\n"
end

# %W(C F G).each { |t| pline line t}
i = 10
20.times do
  pline line TONES[i%12]
  i += 5
end

F#  D   A#
B   G   D#
E   C   G#
A   F   C#
D   A#  F#
G   D#  B
C   G#  E
F   C#  A
A#  F#  D
D#  B   G
G#  E   C
C#  A   F
F#  D   A#
B   G   D#
E   C   G#
A   F   C#
D   A#  F#
G   D#  B
C   G#  E
F   C#  A