Introduction to Chromatic Mediants

What is a Chromatic Mediant?

A chromatic mediant is a type of chord transformation in which the chord root moves by third, and the new chord shares exactly one common tone with the previous one. They come in 8 distinct varieties1:

Examples of an M3M and m8m chromatic mediant:

As you can see, chords related by a chromatic mediants are always of the same mode (major or minor) and are always either a major third or minor third apart, in either direction.

...And make it double!

A doubly chromatic mediant is similar to a normal chromatic mediant, except that the new chord shares no common tones with the original chord. There are only four varieties of doubly chromatic mediants:

Doubly chromatic mediants are always of different modes, and there are only half as many of them!

But what about the others?

The remaining types of mediants (M3m, M9m, m3M, and m8M) are the regular diatonic mediants. They're quite ordinary, as they occur naturally in the major and minor scales.

Where to Find Them

Composers have been writing chromatic mediants since before tonality was established!


1This website uses the Triadic-Tonal Progression Classes (TTPCs) proposed by Scott Murphy in his article "Transformational Theory and the Analysis of Film Music" (2013).