Voice Leading

generator/harmony.py

@@ -72,6 +72,9 @@ def degrees(harmony: dict) -> dict[int, int]:
     raise ValueError('harmony contains no pitch information')
   return result
 
+def is_triad(harmony: dict) -> bool:
+  return set(degrees(harmony)) == {1, 3, 5}
+
 def degree_semitones(degree: int, alter: int) -> int:
   return 12 * ((degree - 1) // 7) + (0, 2, 4, 5, 7, 9, 11)[(degree - 1) % 7] + alter