A music theory tool for composers, artists and learners

  • More than 40 scales you can work with their notes or chords.

  • Select your scale, key and note/chord mode you want to work with.

  • It's virtual keyboard will layout the notes or chords that you can send MIDI to your audio apps via CoreMIDI, Audiobus MIDI or AUv3 MIDI.

Music theory tool

Take advantage of AUv3 Plugin

  • Use it in supporting hosts like AUM, Audiobus 3, Cubasis 2, Beat Maker 3, apeMatrix and Sequencism.

  • Route its MIDI to other AUv3 Synths.

  • Route your MIDI Keyboard's or other MIDI app's MIDI Out to ScaleBud for always playing in scale.

  • In note mode, ScaleBud will filter out off-scale notes.

  • In chord mode, ScaleBud will play chords, if any available in the scale you're working in for the root note you are sending.

Interval sequencer.

Supports Audiobus MIDI Sending and Filtering

  • You can use it in the Audiobus 3 as a MIDI Sender.

    In that mode, you can send the notes/chords from its keyboard.

  • Also, you can use it as a MIDI Filter in Audiobus 3 as well.

    In that mode, it will filter out off-scale notes in scale mode, and sends the chords in chord mode.

Sequencer & Arpeggiator.

Download for iOS

Open source

ScaleBud offers its core componets on Github.
They are all shared libraries for iOS, macOS and tvOS platforms, written in Swift.

Music Theory

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


Send and receive MIDI in human language with Swift enums.


Easy to use Auto Layout tool for iOS and iOS Extensions in Swift.

Other Apps

There are other great music theory apps available.


A music theory app that shows you lots of scales and chords with lots of features.


A music theory app for guitar, bass or any kind of instrument player with frets.


A powerful chord progression app with built-in MIDI sequencer.


MIDI Sequencer and Arpeggiator for iOS.


AUv3 MIDI Music Theory Keyboard for iOS.


AUv3 MIDI Sequencer for iOS.


AUv3 MIDI Rhythm Generator for iOS.

ArpBud 2

AUv3 MIDI Arpeggiator.

ChordBud 2

AUv3 MIDI Chord Sequencer.

Chord Detector

Mac Status Bar App.


AUv3 MIDI Recorder.


Techno Bass Lines.


AUv3 MIDI Sequencer.

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