Sus2 and sus4 chords are revoiced as stacked perfect 4ths. All other chords get quartal reharmonisation suggestions.
How to use: Connect your MIDI keyboard via USB, then allow MIDI access when prompted.
Works in Chrome and Edge. Each new chord you play is recorded in the history below.
Hit Quartal Transform to reharmonise your progression with stacked 4ths, then export to MIDI or text.