Module: Trriad::Chord

Defined in:
lib/trriad/chord.rb,
lib/trriad/chord_data.rb

Constant Summary collapse

CHORDS =

all the different chord notations

{
   "maj"   => "1,3,5".split(','),
   "m"     => "1,3b,5".split(','),
   "7"     => "1,3,5,7b".split(','),
   "6"     => "1,3,5,6".split(','),
   "m6"    => "1,3b,5,6".split(','),
   "maj7"  => "1,3,5,7".split(','),
   "m7"    => "1,3b,5,7".split(','),
   "dim"   => "1,3b,5b,6".split(','),
   "+"     => "1,3,5#".split(','),
   "9"     => "1,3,5,7b,9".split(','),
   "7+5"   => "1,3,5#,7b".split(','),
   "7b5"   => "1,3,5b,7b".split(','),
   "m7b5"  => "1,3b,5b,7b".split(','),
   "m9"    => "1,3b,5,7b,9".split(','),
   "9+5"   => "1,3,5#,7b,9".split(','),
   "9b5"   => "1,3,5b,7b,9".split(','),
   "maj9"  => "1,3,5,7,9".split(','),
   "6add9" => "1,3,5,6,9".split(','),
   "7b9"   => "1,3,5,7b,9b".split(','),
   "7sus4" => "1,4,5,7b".split(','),
   "7add6" => "1,3,5,6,7b".split(','),
   "11"    => "1,3,5,7b,9,11".split(','),
   "11+"   => "1,3,5,7b,9,11#".split(','),
   "11b9"  => "1,3,5,7b,9b,11".split(','),
   "13"    => "1,3,5,7b,9,11,13".split(','),
   "13b9"  => "1,3,5,7b,9b,11,13".split(','),
}
NOTES =

sharp and flat available notes

{
  :sharp => "C,C#,D,D#,E,F,F#,G,G#,A,A#,B".split(","),
  :flat  => "C,Db,D,Eb,E,F,Gb,G,Ab,A,Bb,B".split(",")
}
DISTANCES =

DISTANCES = “2,2,1,2,2,2,1”.split(“,”) the semitone distances for a major key

"2,2,1,2,2,2".split(",")
KEYS =

differentiate the keys with sharps and flats

{
   # since we only have :sharp an :flat, I need to put "C" somewhere
   # so it's in :sharp
   :sharp => "C,G,D,A,E,B,F#,C#".split(","),
   :flat  => "Bb,Eb,Ab,Db,Gb,Cb,Fb".split(","),
}

Class Method Summary collapse

Class Method Details

.get_scale(root) ⇒ Object

get the scale of a root note returns an array of strings with the scale notes



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# File 'lib/trriad/chord.rb', line 25

def self.get_scale(root)
  accitental = nil
  accidental = :flat if KEYS[:flat].include?(root)
  accidental = :sharp if KEYS[:sharp].include?(root)
  
  result="#{root}"
  cur=root
  DISTANCES.each { |distance|
    1.upto(distance.to_i) {
      cur=next_semi(cur,accidental)
    }
    result += ",#{cur}"
  }
  result.split(',')
end

.next_semi(root, accidental = :sharp) ⇒ Object

get the next semi note return the note as a string



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# File 'lib/trriad/chord.rb', line 14

def self.next_semi(root, accidental = :sharp)
  if NOTES[accidental].include?(root) then
    at=NOTES[accidental].index(root)
    tmp=NOTES[accidental] + NOTES[accidental]
    at+=1
    tmp[at]
  end
end

.valid_note(note) ⇒ Object

check if it’s a valid note returns true of false



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# File 'lib/trriad/chord.rb', line 6

def self.valid_note(note)
  NOTES[:sharp].include?(note) ? true : 
  NOTES[:flat].include?(note)  ? true : 
  false
end