Scale Patterns

2026-09-30 03:17:06 -05:00
parent 7cad6db980
commit f5f0ab5eec
31 changed files with 626 additions and 32 deletions
@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+import generator.harmony
+import generator.model
+import generator.pitch
+
+def chord_notes(chord: dict) -> tuple[tuple[int, str], ...]:
+  return tuple((degree, generator.model.pitch_name(generator.pitch.shift_pitch({**chord['root'], 'octave': 4}, degree - 1, generator.harmony.degree_semitones(degree, alter)))) for degree, alter in generator.harmony.degrees(chord).items())
+
+def passage(part: str, solo, choices, library) -> str:
+  lines = [f'{part.capitalize()}: {solo.label}', 'Positions use source measure numbers and quarter-note beats; arranged measure numbers are also shown.', '']
+  lines.append('Scale map:')
+  previous = None
+  for choice in choices:
+    label = choice.scale.label() if choice.scale else 'No exact match within the permitted catalog.' if choice.span.chord else 'N.C.'
+    if label != previous:
+      lines.append(f'  Source measure {choice.span.source_measure}, beat {choice.span.beat}: {label}')
+      lines.append('    ' + choice.reason)
+    previous = label
+  lines.extend(('', 'Chord detail:'))
+  for choice in choices:
+    span, scale = choice.span, choice.scale
+    if span.chord is None:
+      continue
+    chord = span.chord
+    notes = chord_notes(chord)
+    required = [name for _, name in notes]
+    if bass := chord.get('bass'):
+      required.append(generator.model.pitch_name(bass))
+    targets = [name for degree, name in notes if degree in (3, 7)] or [name for _, name in notes]
+    lines.append(f'Source measure {span.source_measure}, beat {span.beat}; arranged measure {span.measure}; offset {span.start} through {span.end}')
+    lines.append('  Chord: ' + generator.harmony.symbol(chord) + '; required pitches: ' + ', '.join(dict.fromkeys(required)))
+    if scale:
+      root = generator.model.pitch_number({**chord['root'], 'octave': 4}) % 12
+      degree, mode = library.chord_mode(scale, generator.model.pitch_name(chord['root'])) if root in scale.pitches else (None, None)
+      lines.append('  Parent: ' + scale.label() + ' [' + ', '.join(scale.notes) + ']')
+      lines.append(f'  Parent degree: {degree or "omitted root"}; chord-root mode: {mode or "not assigned"}')
+      lines.append('  Chord-tone targets: ' + ', '.join(targets))
+      if generator.model.pitch_name(chord['root']) == scale.root:
+        lines.append('  Tonic resolution target: ' + scale.root)
+    else:
+      lines.append('  No exact match within the permitted catalog.')
+    lines.extend(('  Reason: ' + choice.reason, ''))
+  return '\n'.join(lines)