Operations

# Features

- Logical operators
- EnharmonicQ
- EnharmonicClassQ
- SameDurationQ
- Pitch operators
- PitchInstance + Interval
- Duration operations
- Duration + Duration
- Duration - Duration
- Dot[Duration] (Duration + 1/2 Duration)
- Duration * Integer|Rational
- Duration / Integer|Rational
- Duration^-1

# Planned

- Note operators
- Pitch operators
- PitchInstance - Interval
- PitchInstance +/- PitchInstance -> Interval
- Pitch inversion around a point
- Pitch dilation relative to a point
- DiatonicStep +/-

# Maybe

- Pitch set operators