Without difficulty, Liquid Notes, the music production tool that assists you with chords, scales, and harmonic movement makes the theory of harmony accessible, pretty much without restriction.
Just import a MIDI file into Liquid Notes and hit play. Liquid Notes routes the MIDI data back to your sequencer, using all software instruments of your original arrangement. The software will not interfere with your style, handwriting, or emotional message. It simply lets you try out new ideas for your compositions within the vast framework of chords and scales. Liquid Notes delivers suggestions, the final outcome is completely up to you.