Plays the Four Chords used in the I-V-vi-IV progression and the 50s progression which appears frequently in popular music.

This project is inspired by 4chord MIDI a hardware device which does the same thing. It is based on android-midisuite's MidiKeyboard.

This software requires Android Marshmallow (6.0) or later and MIDI support on the device.

This software outputs MIDI using Android's MIDI APIs and requires a synthesiser (not included!) to be able to listen to it. You could use MidiSynthExample Volcano Mobile FluidSynth or an external synth if you connect your device to a USB-MIDI compatible device.

Documentation and source code: https://github.com/micolous/android-fourchords