lukesutton / MusicTheory

Universal music theory library for iOS, macOS, tvOS and watchOS in Swift

MusicTheory

A music theory library with Note, Interval, Scale and Chord representations in swift enums.

Requirements

• Swift 4.0+
• iOS 8.0+
• macOS 10.9+
• tvOS 9.0+
• watchOS 2.0+

Install

pod 'MusicTheorySwift'

Usage

MusicTheory adds a bunch of basic enums and structs that you can define pretty much any music related data. Most importants are Note, Scale and Chord.

NoteType and Note

• All notes defined in NoteType enum.
• You can create Notes with NoteTypes and octaves.
• Also, you can create Notes with MIDI note index.
• Notes and NoteTypes are equatable, + and - custom operators defined for making calulations easier.
• Also, there are other helper functions or properties like frequency of a note.

let d: NoteType = .d
let c = Note(type: .c, octave: 0)

Interval

• Intervals are halfsteps between notes.
• They are IntegerLiteral and you can make add/subsctract them between themselves, notes or note types.
• You can build scales or chords from intervals.
• m2, M2, m3, M3, P4, d5, P5, m6, M6, m7, M7 and P8 are predefined intervals.

ScaleType and Scale

• ScaleType enum defines a lot of readymade scales.
• Also, you can create a custom scale type by ScaleType.custom(intervals: [Interval], description: String)
• Scale defines a scale with a scale type and root key.
• You can generate notes of scale in an octave range.
• Also you can generate HarmonicField of a scale.
• Harmonic field is all possible triad, tetrad or extended chords in a scale.

let c: NoteType = .c
let maj: ScaleType = .major
let cMaj = Scale(type: maj, key: c)

ChordType and Chord

• ChordType is a struct with ChordParts which are building blocks of chords.
• You can define any chord existing with ChordType.
• Thirds, fifths, sixths, sevenths and extensions are parts of the ChordType.
• Each of them also structs which conforms ChordPart protocol.
• Chord defines chords with type and a root key.
• You can generate notes of chord in any octave range.
• You can generate inversions of any chord.

let m13 = ChordType(
  third: .minor,
  seventh: .dominant,
  extensions: [
    ChordExtensionType(type: .thirteenth)
  ])
let cm13 = Chord(type: m13, key: .c)

Tempo and TimeSignature

• Tempo is a helper struct to define timings in your music app.
• TimeSignature is number of beats in per measure and NoteValue of each beat.
• You can calculate notes duration in any tempo by ther NoteValue.
• Note value defines the note's duration in a beat. It could be whole note, half note, quarter note, 8th, 16th or 32nd note.

Documentation

Full documentation are here

Unit Tests

You can find unit tests in MusicTheoryTests target.
Press ⌘+U for running tests.

AppStore

This library battle tested in my apps for iOS, macOS, watchOS and tvOS, check them out!
KeyBud (iOS, watchOS, tvOS, macOS)
FretBud (iOS, watchOS, tvOS)
ChordBud (iOS)