Changes

The mediant relationship between chords is a quite harmonic one, and it's possible to use any combination of mediant chords in succession. We will lose the tonality of the original key by doing so. This prevents a complete resolution and might fail to produce closure for a progression, but makes for a very interesting journey. For example, let's move in mediants and try to return to our tonic:

C E G#m C (= B#)