Chromatic Mediants

     A mediant or submediant relationship refers to the relative distance of a third interval, ascending or descending, to a reference pitch or tonic. In the case of a C major scale, with C being used as reference pitch, its diatonic mediant is an E while its submediant is an A – a major third above and a minor third below, respectively.

     A chromatic mediant is basically a chromatic alteration to the root of a diatonic mediant and submediant that refers to the parallel tonality of the reference pitch or chord; or a chromatic alteration to the third of the available diatonic mediant and submediant chords in that tonality, causing a change in the chord quality. That said, a chromatic mediant relationship can be made in terms of pitch, chords or tonalities.

     Extending the previous example, in C major, its diatonic mediant and submediant are Em and Am while its chromatic mediants would be E and A major, their respective parallel chords. At the same time, the chromatically altered mediant and submediant chords would be Eb and Ab, from the parallel tonality of C minor.

     The chord quality of the chromatic mediants is maintained so that at least one common tone is shared, as shown in the table below:

     As a result, it can be said that C major has four chromatic mediants – E, A, Eb and Ab major; and the other two diatonic mediants – E and A minor; and C minor also has four chromatic mediants – E, A, Eb and Ab minor, with Eb and Ab major as diatonic mediants. Again, all the chromatic mediant relationships share one common tone.

     However, other relationships where no common tones are present can also be considered, as is the case with Abm and Ebm in relation to C major – this is called a double chromatic mediant relationship.

     Altogether, now C major has six chromatic mediants that can be considered in a chord succession – E, A, Eb and Ab major; Eb and Ab minor.

     These relationships became much more common during the romantic period and become even more prominent in post-romantic and impressionistic music, as a tool to create contrasts within the same key, between different keys and to explore chromatic harmonies:

 Chromatic mediant relationship represented with respective color

     Chromatic mediants may appear in either major or minor key contexts and can be used to add freshness and unpredictability to the harmonic direction while prolonging the tonic harmony. These chords may appear before or after the tonic, sometimes the dominant or their own secondary dominants. Or even, as a way to navigate through different tonalities.

Chromatic Mediants and Tonic relationship

     There is also a certain relationship to the tonic because of the parallel modes to which the chromatic mediants belong or can be associated to – i.e. C major and C minor; because of the way that the chord voices resolve and are transformed following the voice-leading principle – similar to dominant seventh chords, chromatic mediants also have two chord tones that resolve chromatically; and the shared common tones between chromatic mediants.

     All that said, chromatic mediant relationships can be used as a way of:

• expanding tonality by neglecting the tonicization of the departure or arrival tonality, maintaining a relationship with those but without confirming them

• introducing multi-functionality from within the same closed tonal system

• allowing smoother modulatory incursions according to the principle of voice-leading, chord transformations and other key relationships;

     The tension between chromatic mediants and the tonic is not the same as the tension between dominants and the tonic. But at the same time, this tension is not less significant than that of the dominant.

     As said, mediants have a relationship to the tonic and tend towards chromatic transformation within the same key while contributing to the tonicization process without recurring to the dominant-tonic cadence.

Nevertheless, dominant chords can be preceded and/or followed by another chromatic mediant dominant chord and each of these have a relation to a tonic, as well as with each other:

Common tones from chromatic mediant chords are represented in green, while the half-step resolutions appear in red.