Function classifyInterval

classifyInterval(semitones: number, twoVoice?: boolean): IntervalQuality
Classify an interval for counterpoint evaluation.

The interval is reduced modulo 12, so compound intervals classify as their simple equivalents. The perfect fourth (5) is context-dependent: with twoVoice (the default) it classifies as a dissonance, matching isConsonantInterval; otherwise it is an imperfect consonance.
Parameters
- semitones: number
  Interval size in semitones (may be negative or compound).
- twoVoice: boolean = true
  When true, the perfect fourth is treated as dissonant.
Returns IntervalQuality
The counterpoint quality of the interval.
Example
```
import { classifyInterval, IntervalQuality } from '@libraz/libcantus';
classifyInterval(7); // IntervalQuality.PerfectConsonance
classifyInterval(5); // IntervalQuality.Dissonance (two-voice)
classifyInterval(5, false); // IntervalQuality.ImperfectConsonance
```
- Defined in core/interval/index.ts:37