Acoustic Comping

generator/comping.py

@@ -67,7 +67,7 @@ def movement(part, previous, current):
 class VoicingCost(typing.NamedTuple):
   extended_grips: int = 0
   family: int = 0
-  effort: int = 0
+  effort: fractions.Fraction = fractions.Fraction()
   missing_tones: int = 0
   register: fractions.Fraction = fractions.Fraction()
   def plus(self, other):
@@ -75,21 +75,36 @@ class VoicingCost(typing.NamedTuple):
   def moved(self, distance):
     return self._replace(effort=self.effort + distance)
 
+def acoustic_preferences(grip, center):
+  """Soft register/hand-position costs, in the same units as finger travel."""
+  policy = generator.vocabulary.role('acoustic_accompaniment').get('voicing', {})
+  register_weight = fractions.Fraction(str(policy.get('register_weight', 1)))
+  position_weight = fractions.Fraction(str(policy.get('high_position_weight', 1)))
+  threshold = fractions.Fraction(str(policy.get('comfortable_max_fret', 9)))
+  if register_weight < 0 or position_weight < 0 or threshold < 1:
+    raise ValueError('acoustic voicing requires nonnegative weights and a positive fret threshold')
+  register = abs(fractions.Fraction(sum(p.midi for p in grip), len(grip)) - center)
+  position = max(fractions.Fraction(), fractions.Fraction(sum(p.fret for p in grip), len(grip)) - threshold)
+  return register_weight * register, position_weight * position
+
 def local_cost(part, key, grip, center):
   required = requirements(json.loads(key), part)
   register = abs(fractions.Fraction(sum(p.midi for p in grip), len(grip)) - center)
   if part == 'electric':
     value = generator.guitar.voicing_cost(grip, 'electric', required.allowed)
     return VoicingCost(value.extended_grips, 3 * value.string_shortfall + value.family_penalty, value.effort, value.missing_tones, register)
-  # Familiar degree orders on either bass string, then whole-form movement.
+  # Familiar degree orders on either bass string, then balanced whole-form
+  # movement, sounding register and hand position. Neither is an absolute ban.
   family = generator.chord_families.acoustic(json.loads(key), grip)
-  return VoicingCost(generator.fretboard.span_penalty(grip), int(not family['preferred']), 0, len(set(required.allowed) - {p.midi % 12 for p in grip}), register)
+  effort = sum(acoustic_preferences(grip, center))
+  return VoicingCost(generator.fretboard.span_penalty(grip), int(not family['preferred']), effort, len(set(required.allowed) - {p.midi % 12 for p in grip}), register)
 
 def select_grips(layers, costs, part, seed, *, left=(), right=(), close=False):
   """Exact small-state dynamic programming; never prune by hand center.
 
   Electric effort includes its melody grip cost and hand-center travel.
-  Acoustic effort follows all four voices, including a bass-string change.
+  Acoustic effort balances register/position with travel of all four voices,
+  including a bass-string change. Compact span and family remain higher tiers.
   Fixing the first grip permits an exact repeat-join cost without a beam.
   """
   if not layers:
@@ -304,6 +319,10 @@ class Canonical:
         'bass_degree': next((d for d, a in degrees.items() if bass and (root + generator.harmony.degree_semitones(d, a)) % 12 == bass.midi % 12), None),
         'bass_string': bass.string_number if bass else None,
         'movement': movement(self.part, previous, grip), 'voicing_candidates': len(span.options)})
+      if grip and self.part == 'acoustic':
+        register, position = acoustic_preferences(grip, self.policy.get('center', 55))
+        travel = movement(self.part, previous, grip)
+        rows[-1]['voicing_cost'] = {'movement': travel, 'register': str(register), 'position': str(position), 'combined': str(travel + register + position)}
       for event in span.events:
         lanes = ['bass', 'upper'] if event.lane == 'combined' else [event.lane]
         for lane in lanes:

generator/production.py

@@ -213,7 +213,14 @@ def _generate_role(source, role, data_dir, settings=None, cache_dir=None):
   trace = {'source': source.musical_key, 'role': role, 'production_resources': inputs['catalogs'],
     'vocabulary': generator.vocabulary.fingerprint(inputs['vocabulary']), 'settings': settings, 'algorithm': algorithm, 'code': inputs['code'], 'cache_key': key}
   choice_source = source.accompaniment_key() if role.endswith('_accompaniment') else source.musical_key
-  seed = generator.vocabulary.fingerprint({'source': choice_source, 'role': role, 'settings': settings, 'data': inputs['vocabulary'], 'version': algorithm})
+  choice_data, choice_settings = inputs['vocabulary'], settings
+  if role == 'acoustic_accompaniment':
+    # Voicing weights invalidate the concrete cache, but must not reshuffle
+    # rhythm patterns. Removing this new field preserves the pre-policy seed.
+    choice_data = copy.deepcopy(choice_data)
+    choice_data['roles']['role'].pop('voicing', None)
+    choice_settings = {k: v for k, v in settings.items() if k != 'voicing'}
+  seed = generator.vocabulary.fingerprint({'source': choice_source, 'role': role, 'settings': choice_settings, 'data': choice_data, 'version': algorithm})
   details = {}
   solo_report = ''
   composition_timings = {}