def _Rule_10(s: stave.Stave):
"""Éviter les marches d'harmonie"""
for start in range(s.barNumber):
for end in range(start, s.barNumber):
motif = []
for i in range(start, end + 1):
for n in s.getBar(i):
motif.append(n)
motif_bar_number = end - start + 1
try:
following = []
for i in range(end + 1, motif_bar_number + end + 1):
for n in s.getBar(i):
following.append(n)
except IndexError:
break
try:
if tools.matchSequence(motif, following, s.scale):
msg = f"Sequence in {s.title}. It should be avoided"
if len(motif) == 1:
continue
if len(motif) <= 2:
error.warn(msg, motif, following)
else:
raise error.CompositionError(msg, motif, following)
except ValueError:
# It should be that the relative one is encountered, so no sequence here
continue
def rule_4(s: stave.Stave):
"""On doit commencer par une consonance parfaite (unisson, quinte ou douzième, octave ou quinzième) et finir par l'octave ou l'unisson
"""
def nb_error(poss, posi, notes):
if len(notes) != 2:
raise error.CompositionError(
f"Two notes are expected at the {poss} of the track",
s.getBar(posi))
# start
notes = s.atFirstPos(0)
nb_error("start", 0, notes)
if not notes[0].pitch.isPerfectlyConsonantWith(notes[1].pitch):
raise error.CompositionError(
"The first two notes are not fully consonant.", s.getBar(0))
# end
notes = s.atFirstPos(s.lastFirstPos)
nb_error("end", s.getBar(s.barNumber - 1), notes)
if not notes[0].pitch.isInterval(1, 8, True).With(notes[1].pitch):
raise error.CompositionError(
"The last interval must be an unison or an octave.",
s.getBar(s.barNumber - 1))
def rule_23(s: stave.Stave):
"""La première et la dernière mesure sont obligatoirement harmonisées par l'accord de tonique à l'état fondamental"""
c = chord.Chord(1, s.scale)
for bar in (s.getBar(0), s.getBar(-1)):
if not c.isInversion([*bar], 0):
raise error.CompositionError(
"First and last bar must be at the root position of the chord of the first degree",
bar)
def rule_26(s: stave.Stave):
"""La première et la dernière mesure sont obligatoirement harmonisées par l'accord de tonique à l'état fondamental"""
tonic = chord.Chord(1, s.scale)
for measure in (s.getBar(0), s.getBar(-1)):
is_error = False
try:
if not tonic.isInversion([*measure], 0):
is_error = True
except ValueError:
is_error = True
if is_error:
raise error.CompositionError(
f"In {s.title}, the first bar or the last bar is not the tonic chord at root position",
measure)
def rule_22(cp: stave.Stave, cf: stave.Stave):
"""À l'avant dernière mesure, on emploiera la sixte majeure lorsque le chant donné sera à la basse et la tierce mineure suivie de l'octave ou de l'unisson lorsqu'il sera à la partie supérieure"""
# is the cantus firmus above or beyond?
cp_above = None
for cpn, cfn in zip(cp.barIter(), cf.barIter()):
cpn, cfn = [util.to_pitch(n[0]) for n in (cpn, cfn)]
if cpn != cfn:
cp_above = cpn.value.step > cfn.value.step
break
assert cp_above is not None
# check the before last one bar
cpn = util.to_pitch(cp.getBar(cp.barNumber - 2)[0])
cfn = util.to_pitch(cf.getBar(cf.barNumber - 2)[0])
cp = cp.copy()
cp.extend(cf)
before_last_bar = cp.getBar(cp.barNumber - 2)
if cp_above and not cfn.isQualifiedInterval((6, "major")):
raise error.CompositionError(
"The before last interval must be a 6th major", before_last_bar)
elif not cp_above and not cfn.isQualifiedInterval((3, "minor")):
raise error.CompositionError(
"The before last interval must be a 3rd minor", before_last_bar)
def rule_14(s: stave.Stave):
"""Pour la fausse relation de triton, la règle est la même qu'en harmonie : la fausse relation de triton est défendue."""
get_pitches = lambda b: sorted([util.to_pitch(x) for x in b],
key=lambda x: x.value.semitone)
old_high = None
for i, bar in enumerate(s.barIter()):
if len(bar) != 2:
raise error.CompositionError("Two notes expected", bar)
bass, high = get_pitches(bar)
# check with last bar
if old_high is not None and bass.isQualifiedInterval(
(4, 'augmented')).With(old_high):
raise error.CompositionError("False relation is forbidden", bar)
# check with next bar
if i + 1 < s.barNumber:
next_bass, next_high = get_pitches(s.getBar(i + 1))
if bass.isQualifiedInterval((4, 'augmented')).With(next_high):
raise error.CompositionError("False relation is forbidden",
bar)
# prepare next iteration
old_high = high