Class: Stretto::MusicElements::Chord

Inherits:

MusicElement

• Object
• MusicElement
• Stretto::MusicElements::Chord

show all

Extended by:

Forwardable

Includes:

AttackDecay, Duration

Defined in:

lib/stretto/music_elements/chord.rb,
lib/stretto/music_elements/modifiers/chord_intervals.rb

Overview

Constant Summary

DEFAULT_OCTAVE =

3

CHORD_INTERVALS =

The literal names of chord intervals. Values represent the semitones from the base note of the notes that form the chord.

{
  'maj'       => [4, 7],
  'min'       => [3, 7],
  'aug'       => [4, 8],
  'dim'       => [3, 6],
  'dom7'      => [4, 7, 10],
  'maj7'      => [4, 7, 11],
  'min7'      => [3, 7, 10],
  'sus4'      => [5, 7],
  'sus2'      => [2, 7],
  'maj6'      => [4, 7, 9],
  'min6'      => [3, 7, 9],
  'dom9'      => [4, 7, 10, 14],
  'maj9'      => [4, 7, 11, 14],
  'min9'      => [3, 7, 10, 14],
  'dim7'      => [3, 6, 9],
  'add9'      => [4, 7, 14],
  'min11'     => [7, 10, 14, 15, 17],
  'dom11'     => [7, 10, 14, 17],
  'dom13'     => [7, 10, 14, 16, 21],
  'min13'     => [7, 10, 14, 15, 21],
  'maj13'     => [7, 11, 14, 16, 21],
  'dom7<5'    => [4, 6, 10],
  'dom7>5'    => [4, 8, 10],
  'maj7<5'    => [4, 6, 11],
  'maj7>5'    => [4, 8, 11],
  'minmaj7'   => [3, 7, 11],
  'dom7<5<9'  => [4, 6, 10, 13],
  'dom7<5>9'  => [4, 6, 10, 15],
  'dom7>5<9'  => [4, 8, 10, 13],
  'dom7>5>9'  => [4, 8, 10, 15]
}

Constants included from AttackDecay

AttackDecay::DEFAULT_ATTACK, AttackDecay::DEFAULT_DECAY

Constants included from Duration

Duration::DEFAULT_DURATION, Duration::DEFAULT_TUPLET_DENOMINATOR, Duration::DEFAULT_TUPLET_NUMERATOR, Duration::DURATIONS

Instance Attribute Summary (collapse)

• - (Object) instrument

  Returns the value of attribute instrument.

• - (Object) key_signature

  Returns the value of attribute key_signature.

• - (Object) named_chord readonly

  Returns the value of attribute named_chord.

• - (Object) original_named_chord readonly

  Returns the value of attribute original_named_chord.

Attributes included from AttackDecay

#original_attack, #original_decay

Attributes included from Duration

#end_tie, #original_duration, #start_tie

Attributes inherited from MusicElement

#original_string, #pattern

Attributes included from Node

#next, #prev

Instance Method Summary (collapse)

• - (Boolean) ==(other)

  True if all the notes of the chord are equal.

• - (Object) base_note

  Returns the base note of the chord, that is, the note the chord was specified with.

• - (Chord) initialize(string_or_options, pattern = nil) constructor

  A new instance of Chord.

• - (Number) inversions

  The number of inversions of the chord.

• - (Array(MusicElements::Note)) notes

  The array of notes generated by this chord.

• - (MusicElements::Note) pivot_note

  The pivot note in which do the inversion, if specified.

Methods included from AttackDecay

#attack, #attack=, #build_attack_and_decay, #decay, #decay=

Methods included from Duration

#build_duration_from_token, #duration, #end_of_tie?, parse_duration, #start_of_tie?, #tied_duration, #tied_elements

Methods inherited from MusicElement

#build_music_string, #duration, #end_of_tie?, #start_of_tie?, #to_s

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# File 'lib/stretto/music_elements/chord.rb', line 54

def initialize(string_or_options, pattern = nil)
  token = case string_or_options
    when String then Stretto::Parser.parse_chord!(string_or_options)
    else string_or_options
  end
  super(token[:text_value], pattern)
  unless @notes = token[:notes]
    build_duration_from_token(token[:duration])
    @original_base_note   = token[:base_note]
    @original_named_chord = token[:named_chord]
    @named_chord          = @original_named_chord.downcase
    @original_inversions  = token[:inversions]
    @base_note            = base_note
    build_attack_and_decay(token[:attack], token[:decay])
  end
end

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# File 'lib/stretto/music_elements/chord.rb', line 44

def instrument
  @instrument
end

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# File 'lib/stretto/music_elements/chord.rb', line 43

def key_signature
  @key_signature
end

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# File 'lib/stretto/music_elements/chord.rb', line 42

def named_chord
  @named_chord
end

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# File 'lib/stretto/music_elements/chord.rb', line 42

def original_named_chord
  @original_named_chord
end

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# File 'lib/stretto/music_elements/chord.rb', line 91

def ==(other)
  notes && notes == other.notes
end

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# File 'lib/stretto/music_elements/chord.rb', line 85

def base_note
  @base_note || build_base_note(@original_base_note)
end

Chord.new("Cmaj^^").inversions # => 2

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# File 'lib/stretto/music_elements/chord.rb', line 98

def inversions
  build_inversions unless @inversions
  @inversions
end

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# File 'lib/stretto/music_elements/chord.rb', line 72

def notes
  unless @notes
    build_chord_notes(@named_chord)
    build_inversions
  end
  @notes
end

Chord.new("Cmaj^E").pivot_note # => Note<@key="E">

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# File 'lib/stretto/music_elements/chord.rb', line 106

def pivot_note
  build_inversions unless @pivot_note
  @pivot_note
end