A specific voice-leading problem detected between two voices.
Readable description, with voices numbered from 1 ('Parallel 5ths (Voices 1 and 3)').
'Parallel 5ths (Voices 1 and 3)'
What the problem is.
Indices of the voices involved, as ordered in the arrays passed in (0 = first note).
A specific voice-leading problem detected between two voices.