Pitches.jl

A library for handling musical pitches and intervals in a systematic way. For other (and mostly compatible) implementations see:

• pitchtypes (Python)
• a Haskell implementation
• purescript-pitches (Purescript)
• pitches.rs (Rust)

Overview

This library defines types for musical intervals and pitches as well as a generic interface for writing algorithms that work with different pitch and interval types. For example, you can write a function like this

transposeby(pitches, interval) = [pitch + interval for pitch in pitches]

and it will work with any midi pitch:

julia> transposeby((@midip [60, 63, 67]), midi(3))
3-element Array{Pitch{MidiInterval},1}:
 p63
 p66
 p70

... midi pitch classes:

julia> transposeby(map(midipc, [3,7,10]), midic(3))
3-element Array{Pitch{MidiIC},1}:
 pc6
 pc10
 pc1

... spelled pitch:

julia> transposeby([p"C4", p"E4", p"G4"], i"m3:0")
3-element Array{Pitch{SpelledInterval},1}:
 E♭4
 G4
 B♭4

... spelled pitch classes:

julia> transposeby([p"C", p"E", p"G"], i"m3")
3-element Array{Pitch{SpelledIC},1}:
 E♭
 G
 B♭

... or any other pitch type.