generate MIDI note names/numbers in YAML format

midi_notes_to_yaml.rb

# generate MIDI note names/numbers in YAML format

octaves = (0..10)
range = (0..127)

naturals = [
  { :name => "C", :val => 0 },
  { :name => "D", :val => 2 },
  { :name => "E", :val => 4 },
  { :name => "F", :val => 5 },
  { :name => "G", :val => 7 },
  { :name => "A", :val => 9 },
  { :name => "B", :val => 11 }
]

notes = []

# add accidentals and enharmonic equivalents
naturals.each do |note|
  notes.push(note)
  ind = notes.index(note)
  notes.insert(ind, { :name => "#{note[:name]}b", :val => note[:val]-1 })
  notes.insert(ind+2, { :name => "#{note[:name]}#", :val => note[:val]+1 })
end

# create full list
list = []

octaves.each do |oct|
  notes.each do |note|
    note_name = note[:name] + ((oct - 1).to_s)
    note_num = (note[:val] + (oct * 12))
    list << { :name => note_name, :val => note_num } if range.include?(note_num)
  end
end

# sort putting unusual enharmonic equivalents last
list.sort! do |a,b| 
  c = (a[:val] <=> b[:val])
  aa = a[:name].include?("b") || a[:name].include?("#") ? 1 : 0
  ba = b[:name].include?("b") || b[:name].include?("#") ? 1 : 0
  c.zero? ? aa <=> ba : c
end

# output
puts("Notes:\n")
list.each do |note|
  puts("  #{note[:name]}: #{note[:val].to_s}\n")
end