The Chromatic Mediant
Two major chords a third apart that do not belong to the same key. They share one note and disagree about everything else, which is why the move sounds like the ground shifting rather than like a chord change.
- 2 chords
- a third apart
- one shared note
same family
The progression
I - bVI - I - III
Why it works
Normal chord changes keep you inside a key: the chords share two notes and the shift is small. A chromatic mediant shares only one. That is enough for your ear to hear the two chords as related, and little enough that the new chord sounds like it came from somewhere else entirely. The effect is a sudden change of light without the song ever announcing a key change, which is why it has become the default gesture for wonder and for dread in film music.
Hear it in context
Three of our own examples: the two pairs as orchestral swells, as a synth progression and directly next to a normal I - vi so the difference in distance is clear.
Make it yours
- Keep the shared note on top
It is the thread that stops the move sounding random.
- Only use one
Two chromatic mediants in a row and the song has no key left to shift away from.
- Try both directions
Down to the bVI is awe, up to the III is menace, and the mechanism is identical.
When to reach for it
For the moment something changes scale: a reveal, a horizon, a threat. For progressions that must sound modern without sounding jazzy.
When to leave it alone
For a song that needs a stable key. This move deliberately weakens the key centre and it does not ask permission.