def bass_note_tendency_score(candidate, beat):
this_chord = chords.get(beat.start())
score = 0.0
candidate_is_this_chord_bass_note = pitches.same_species(candidate, this_chord.bass_note)
# first bass note should definitely be the root
if beat.start() == 0 and candidate_is_this_chord_bass_note:
return vars.FIRST_BEAT_BASS_ROOT
# If beat one, we want to hear the bass note
if beat.first_beat() and candidate_is_this_chord_bass_note:
score += vars.FIRST_BEAT_BASS_NOTE
last_chord = chords.get(0 if beat.start() == 0 else beat.previous().start())
this_and_next_chord_are_same = chords.same(last_chord, this_chord)
this_chord_root_in_bass = this_chord.root_in_bass()
# Chord is the same as the last chord, and this is root note. Less important as root was likely
# already established
if this_and_next_chord_are_same and candidate_is_this_chord_bass_note and this_chord_root_in_bass:
score += vars.BASS_ROOT_SAME_CHORD
# Bass note does not equal root note, therefore it is especially important
if pitches.same_species(candidate, this_chord.bass_note) and not this_chord_root_in_bass:
score += vars.NON_ROOT_BASS_NOTE
# new chord, we definitely want to hear the bass_note
if not this_and_next_chord_are_same and candidate_is_this_chord_bass_note:
score += vars.BASS_NOTE_NEW_CHORD
return score
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return pitches.same_species(other.bass_note,
self.bass_note) and pitches.same_species(
other._root, self._root)
def functional_relevance(self, c1, c2):
score = _KeySignature.functional_relevance(self, c1, c2)
if self.is_functional(c1) and self.is_functional(c2) and \
pitches.same_species(c1.root(), self.five()) and pitches.same_species(c2.root(), self.flat_six()):
score += vars.FIVE_SIX_FUNCTIONALITY
return score
def third_preference_score(candidate, beat):
chord = chords.get(beat.start())
if isinstance(chord, chords.SevenChord):
if [pitch for pitch in candidate if pitches.same_species(pitch, chord.three())]:
return vars.THIRD_PREFERENCE
return 0.0
def __contains_one_or_five_seven(key_signature, chord_progression_stub):
for key in chord_progression_stub.keys():
chord = chord_progression_stub[key]
if key_signature.is_functional(chord) and pitches.same_species(
key_signature.one(), chord.root()):
return True
return False
def harmonic_relevance(self, chord):
if pitches.same_species(chord.root(), self.one()) and \
isinstance(chord, chords.MinorChord):
return vars.ONE_CHORD_HARMONY
elif pitches.same_species(chord.root(), self.two()) and \
isinstance(chord, chords.DiminishedChord):
return vars.TWO_CHORD_HARMONY
elif pitches.same_species(chord.root(), self.three()) and \
isinstance(chord, chords.MajorChord):
return vars.THREE_CHORD_HARMONY
elif pitches.same_species(chord.root(), self.four()) and \
isinstance(chord, chords.MinorChord):
return vars.FOUR_CHORD_HARMONY
elif pitches.same_species(chord.root(), self.flat_six()) and \
isinstance(chord, chords.MajorChord):
return vars.SIX_CHORD_HARMONY
return _KeySignature.harmonic_relevance(self, chord)
def harmonic_relevance(self, chord):
"""
Some chords are more indicative of a certain key than other. E.g. in C, the chords C and G7 strongly
indicate that we're in the key of C. Returns a score based on harmonic relevance to the key
:param chord: chords.Chords object
:return: Harmony relevance score
"""
if pitches.same_species(chord.root(), self.five()) and \
isinstance(chord, chords.SevenChord):
return vars.FIVE_DOMINANT_HARMONY
elif pitches.same_species(chord.root(), self.five()) and \
isinstance(chord, chords.MajorChord):
return vars.FIVE_MAJOR_HARMONY
elif pitches.same_species(chord.root(), self.seven()) and \
isinstance(chord, chords.DiminishedChord):
return vars.MAJOR_SEVEN_DIMINISHED_HARMONY
return 0.0
def preemption_penalty(candidate, beat):
if beat.end() == config.song_length:
return 0.0
this_chord = chords.get(beat.start())
next_chord = chords.get(beat.next().start())
if pitches.same_species(candidate, next_chord.root()) and this_chord != next_chord:
return vars.PREEMPTION
return 0.0
def __get_musicality(self):
score = 0.0
next_pitch = self.sequence[self.position + config.resolution].midi()
next_chord = config.chord_progression[self.position +
config.resolution]
next_key = config.key_signatures[self.position + config.resolution]
this_key = config.key_signatures[self.position]
if pitches.same_species(next_pitch, next_chord.root()):
y = this_key != next_key
s = next_chord.root()
e = next_key.one()
t = pitches.same_species(next_chord.root(), next_key.one())
score += vars.APPROACH_KEY_CHANGE \
if pitches.same_species(next_chord.root(), next_key.one()) and this_key != next_key \
else vars.APPROACH_NEW_CHORD_ROOT
else:
score += vars.APPROACH_DEFAULT_MUSICALITY
score += vars.FLICKER_COEF if self.causes_flickering() else 0.0
return score
def is_functional(self, chord):
chord_root = chord.root()
if (pitches.same_species(chord_root, self.three()) or
pitches.same_species(chord_root, self.flat_six()) or
pitches.same_species(chord_root, self.five())) and \
isinstance(chord, chords.MajorChord):
return True
elif (pitches.same_species(chord_root, self.five())) \
and isinstance(chord, chords.SevenChord):
return True
elif (pitches.same_species(chord_root, self.one()) or
pitches.same_species(chord_root, self.four())) and \
isinstance(chord, chords.MinorChord):
return True
elif (pitches.same_species(chord_root, self.seven() or
pitches.same_species(chord_root, self.two())) and
isinstance(chord_root, chords.DiminishedChord)):
return True
return False
def root_in_bass(self):
return pitches.same_species(self._root, self.bass_note)
def functional_relevance(self, c1, c2):
"""
Some functional relationships are more indicative of some key sigantures. E.g. A7 -> D is strongly
indicative of the key of D. Returns a score based on how functionally relevant the two chords are in this key.
* Not currently implemented: The dimension of time needs to be included within the scoring mechanism.
The following example illustrates why. Assume we're in 4/4 and the actual key signature is A
| A | | | || D | | | || F- | | | ||
Why humans can deduce that this relationship is indicative of A, the computer just see A -> D, which is
more indicative of the key of D. The F- could be any chord that would force a key change to be registered.
:param c1: first chord
:param c2: second chord
:return: functionality score based on the chords
"""
score = 0.0
if self.is_functional(c1) and self.is_functional(c2):
# Dominant five chords in functional relationship are more valuable than just major fives
if (pitches.same_species(c1.root(), self.five()) and isinstance(c1, chords.SevenChord)) or \
(pitches.same_species(c2.root(), self.five()) and isinstance(c2, chords.SevenChord)):
score += vars.DOMINANT_FIVE_IN_FUNCTIONAL_RELEVANCE
elif (pitches.same_species(c1.root(), self.five()) and isinstance(c1, chords.MajorChord)) or \
(pitches.same_species(c2.root(), self.five()) and isinstance(c2, chords.MajorChord)):
score += vars.MAJOR_FIVE_IN_FUNCTIONAL_RELEVANCE
if pitches.same_species(c1._root, self.five()) and pitches.same_species(c2._root, self.one()):
score += vars.FIVE_ONE_FUNCTIONALITY
elif pitches.same_species(c1._root, self.seven()) and pitches.same_species(c2._root, self.one()):
score += vars.SEVEN_ONE_FUNCTIONALITY
elif pitches.same_species(c1._root, self.two()) and pitches.same_species(c2._root, self.five()):
score += vars.TWO_FIVE_FUNCTIONALITY
elif pitches.same_species(c1._root, self.four()) and pitches.same_species(c2._root, self.five()):
score += vars.FOUR_FIVE_FUNCTIONALITY
return score