Test whether an interval is a perfect consonance: the unison/octave or the
fifth.
The perfect fourth is deliberately excluded. This is the predicate the
parallel-motion rules are written against, where the fourth behaves as a
dissonance between two voices; classifyInterval is the general
classifier, and it treats the fourth as context-dependent.
Parameters
semitones: number
Interval size in semitones (may be negative or compound).
Returns boolean
True for the unison/octave (0) and the perfect fifth (7) mod 12.
Test whether an interval is a perfect consonance: the unison/octave or the fifth.
The perfect fourth is deliberately excluded. This is the predicate the parallel-motion rules are written against, where the fourth behaves as a dissonance between two voices; classifyInterval is the general classifier, and it treats the fourth as context-dependent.