def slices_to_melodic_intervals(first,
second) -> Tuple[NamedInterval, NamedInterval]:
first_lower = first.leaves[0]
second_lower = second.leaves[0]
first_upper = first.leaves[1]
second_upper = second.leaves[1]
lower = NamedInterval.from_pitch_carriers(first_lower, second_lower)
upper = NamedInterval.from_pitch_carriers(first_upper, second_upper)
return lower, upper
def grade_composition(self, composition: CompositionEnvironment) -> int:
penalties = 0
working_staff = StaffGroup()
working_staff.append(composition.voices[0])
working_staff.append(composition.voices[1])
interval_tally = {}
pitch_tally = {}
melodic_interval_tally = {}
vertical_moments = list(iterate(working_staff).by_vertical_moment())
intervals = []
degrees = [[], []]
for moment in vertical_moments:
pitches = moment.leaves
harmonic = NamedInterval.from_pitch_carriers(
pitches[1], pitches[0])
intervals.append(harmonic)
degrees[0].append(
composition.composition_parameters.scale.
named_pitch_class_to_scale_degree(pitches[0]))
degrees[1].append(
composition.composition_parameters.scale.
named_pitch_class_to_scale_degree(pitches[1]))
count = pitch_tally.setdefault(pitches[0], 0) + 1
pitch_tally[pitches[0]] = count
count = pitch_tally.setdefault(pitches[1], 0) + 1
pitch_tally[pitches[1]] = count
count = interval_tally.setdefault(harmonic, 0) + 1
interval_tally[harmonic] = count
for i in range(len(vertical_moments)):
vertical_moment = vertical_moments[i]
harmonic = intervals[i]
# No voice crossing
if harmonic.direction_string == "descending":
penalties -= 1
if abs(harmonic.semitones) in constants.dissonant_intervals:
penalties -= 5
# No harmonic intervals greater than a 12th
if abs(harmonic.semitones) > NamedInterval("P12").semitones:
penalties -= 5
# Tenth is pushing it
elif abs(harmonic.semitones) > NamedInterval("M10").semitones:
penalties -= 1
maximum_extent = vertical_moment.offset + vertical_moment.leaves[
0].written_duration
if maximum_extent == composition.composition_parameters.duration:
last_top = degrees[0][-1]
last_bottom = degrees[1][-1]
prev_top = degrees[0][-2]
prev_bottom = degrees[1][-2]
# Use an authentic cadence
if last_top != ScaleDegree(1):
penalties -= 10
if last_bottom != ScaleDegree(1):
penalties -= 10
if not ((prev_top == ScaleDegree(7)
and prev_bottom == ScaleDegree(2)) or
(prev_top == ScaleDegree(2)
and prev_bottom == ScaleDegree(7))):
penalties -= 10
elif i is 0:
# First interval should be a tonic unison
if degrees[0][0] != ScaleDegree(1):
penalties -= 5
if degrees[1][0] != ScaleDegree(1):
penalties -= 5
if i > 0:
prev_harmonic = intervals[i - 1]
prev_slice = vertical_moments[i - 1]
lower_melodic, upper_melodic = slices_to_melodic_intervals(
prev_slice, vertical_moment)
count = melodic_interval_tally.get(lower_melodic, 0) + 1
melodic_interval_tally[lower_melodic] = count
count = melodic_interval_tally.get(upper_melodic, 0) + 1
melodic_interval_tally[upper_melodic] = count
motion = characterize_relative_motion(upper_melodic,
lower_melodic)
# Lines should always be moving
if motion is RelativeMotion.none:
penalties -= 5
# Contrary motion is preferred
if motion is RelativeMotion.similar or motion is RelativeMotion.oblique:
penalties -= 1
# Never have two perfect consonances in a row
if prev_harmonic.interval_class == harmonic.interval_class and harmonic.quality_string == "perfect":
penalties -= 5
# Steps are preferred to leaps
if is_leap(lower_melodic):
penalties -= 1
if is_leap(upper_melodic):
penalties -= 1
if i > 2:
prev_prev_harmonic = intervals[i - 2]
prev_prev_prev_harmonic = intervals[i - 3]
all_same = same_harmonic_quality(harmonic, prev_harmonic,
prev_prev_harmonic,
prev_prev_prev_harmonic)
# Don't have the same interval more than three times in a row
if all_same:
penalties -= 5
prev_lower_melodic, prev_upper_harmonic = slices_to_melodic_intervals(
vertical_moments[i - 2], prev_slice)
# Encourage counterstepwise motion.
# If the prev motion was a leap..
if is_leap(prev_lower_melodic):
# It needs to be resolved by a step, and the step needs to be in the opposite direction
if not is_step(lower_melodic) or (
prev_lower_melodic.semitones >
0 ^ lower_melodic.semitones > 0):
penalties -= 5
else:
()
# print("we did it")
if is_leap(prev_upper_harmonic):
if not is_step(upper_melodic) or (
prev_upper_harmonic.semitones >
0 ^ upper_melodic.semitones > 0):
penalties -= 5
else:
()
# print("we did it")
"""
for pitch, num in pitch_tally.items():
if num > 2:
penalties -= 5 * num
for interval, num in interval_tally.items():
if num > 5:
penalties -= 5 * num
for interval, num in melodic_interval_tally.items():
if num > 5:
penalties -= 5 * num
"""
return penalties
def interval_or_none(first, second):
if first is None or second is None:
return None
else:
return NamedInterval.from_pitch_carriers(first, second)
def reward(self, state, action, state_prime):
if NamedInterval.from_pitch_carriers(
self.domain.voices[1][-1],
self.domain.voices[0][-1]).semitones != 4:
return -1
return 0