Comping

generator/vocabulary.py

@@ -23,25 +23,44 @@ def _load(contents):
   result = {}
   for name, text in contents:
     value = json.loads(text)
-    if value.get('version') != (3 if name == 'accompaniment' else 1) or not value.get('provenance') or not value.get('license'):
+    if value.get('version') != (4 if name == 'accompaniment' else 1) or not value.get('provenance') or not value.get('license'):
       raise ValueError(f'{name}: unsupported or unprovenanced production vocabulary')
     if name == 'accompaniment':
-      if fractions.Fraction(value['grid']) != fractions.Fraction(1, 2):
-        raise ValueError('accompaniment requires an eighth-note placement grid')
-      for part, lanes in (('electric', ('electric',)), ('acoustic', ('bass', 'upper'))):
+      signatures = {}
+      for part in ('electric', 'acoustic'):
         policy = value['instruments'][part]
-        if fractions.Fraction(policy['attack_spacing']) < fractions.Fraction(1, 2):
-          raise ValueError('accompaniment attacks must be at least an eighth apart')
-        for lane in lanes:
-          layer = policy['layers'][lane]
-          if not 0 <= layer['attacks'][0] <= layer['attacks'][1] <= 3 or not layer['families']:
-            raise ValueError('invalid accompaniment attack range or duration families')
-          for family in layer['families']:
-            durations = policy['families'][family]
-            if not durations or any(fractions.Fraction(d) <= 0 for d in durations):
-              raise ValueError('accompaniment durations must be positive')
-            if part == 'acoustic' and any(fractions.Fraction(d) not in (fractions.Fraction(1, 2), 1) for d in durations):
-              raise ValueError('acoustic rhythm uses quarter and eighth notes')
+        identifiers = set()
+        signatures[part] = set()
+        for pattern in policy['patterns']:
+          if pattern['id'] in identifiers or not pattern['family']:
+            raise ValueError('duplicate or unnamed accompaniment pattern')
+          identifiers.add(pattern['id'])
+          lengths = tuple(map(fractions.Fraction, pattern['lengths']))
+          if not 1 <= len(lengths) <= 2 or any(n <= 0 for n in lengths):
+            raise ValueError('patterns require one or two positive measure lengths')
+          # Validate musical events before any measure projection or ties.
+          previous = fractions.Fraction()
+          onsets = []
+          for row in pattern['events']:
+            onset, duration = fractions.Fraction(row['onset']), fractions.Fraction(row['duration'])
+            if onset < previous or duration <= 0 or onset + duration > sum(lengths):
+              raise ValueError('overlapping or out-of-bounds accompaniment pattern')
+            if onset.denominator > 2 or duration.denominator > 2:
+              raise ValueError('comping vocabulary uses a quarter/eighth grid')
+            if part == 'acoustic':
+              if row['layer'] == 'combined':
+                if duration <= 1:
+                  raise ValueError('combined acoustic sustain must exceed one beat')
+              elif row['layer'] not in ('bass', 'upper') or duration not in (fractions.Fraction(1, 2), 1):
+                raise ValueError('acoustic short attacks require bass/upper quarter/eighth notes')
+            elif row['layer'] != 'electric':
+              raise ValueError('electric pattern must contain electric chord attacks')
+            if row.get('anticipate') and row['layer'] not in ('upper', 'electric'):
+              raise ValueError('only upper/electric chords can anticipate')
+            previous = onset + duration
+            onsets.append(onset)
+          if len(lengths) == 2:
+            signatures[part].add((lengths, tuple(onsets)))
         families = policy['voicing_families']
         if not families.get('provenance'):
           raise ValueError('guitar voicing families require provenance')
@@ -49,16 +68,16 @@ def _load(contents):
           if set(families['rank']) != {'drop-two', 'close-position', 'compact-open', 'compact-doubled', 'three-note-shell'} or any(type(v) is not int or not 0 <= v <= 2 for v in families['rank'].values()):
             raise ValueError('invalid electric family ranking')
         else:
-          if set(map(fractions.Fraction, policy['allowed_durations'])) != {fractions.Fraction(1, 2), fractions.Fraction(1)} or policy['connect_holds']:
-            raise ValueError('acoustic rhythm must retain short quarter/eighth attacks')
           for kind in ('triad', 'tetrad', 'extended'):
             if set(families[kind]) != {'5/1', '5/5', '6/1', '6/5'}:
               raise ValueError('acoustic families require root/fifth bass on both bass strings')
             for orders in families[kind].values():
               if not orders or any(len(o) != 3 or set(o) - {'root', 'fifth', 'guide', 'terminal', 'color'} for o in orders):
                 raise ValueError('invalid acoustic upper chord order')
-      if not 1 <= value['lane_candidates'] <= 64 or not 1 <= value['measure_candidates'] <= 64:
-        raise ValueError('accompaniment candidate budgets must be 1–64')
+      if signatures['acoustic'] & signatures['electric']:
+        raise ValueError('acoustic/electric two-bar onset patterns must be distinct')
+      if not 1 <= value['pattern_candidates'] <= 64:
+        raise ValueError('accompaniment pattern budget must be 1–64')
     entries = value.get('cells', value.get('patterns', value.get('colors', value.get('transformations', []))))
     if len({v['id'] for v in entries}) != len(entries):
       raise ValueError(f'{name}: duplicate vocabulary ID')