In this video I'll try to show you the difference in sound between tertiary harmony (the chords you already know) and quartal harmony.
Remember that we're not dealing with functional harmony anymore so we can play any of the quartal chords from the key and their function is only changed by what the bass player plays. Therefore you'll hear me play many more chords in the quartal version than the tertiary version.
Quartal chords work best in a modal scenario so I've chosen the key of Bb for this example and used its 2nd mode - C dorian.
Move onto the next video to learn the shapes for C dorian on the middle 4 strings.