Chapters in Development
Mediants
Mark Gotham
Key Takeaways
- Grade 1 (a.k.a. Diatonic): 2 common tones; mode change (between major and minor).
- Grade 2 (a.k.a. Chromatic): 1 common tone; mode preserved (e.g., both major).
- Grade 3 (a.k.a. Disjunct, Doubly-Chromatic): No common tones; mode change.
A key focus of the previous chapter on neo-Riemannian progressions, is the connection between triads with roots a third apart. For instance, the L-relation connects C-major with E-minor (in either direction). Another way of looking at these third-related chords is in terms of “mediants”. Recall from fundamentals that the third and sixth scale degrees are sometimes called the “mediant” and “submediant”. Again, these are a third away from the tonic.
What does this have to do with chromatic harmony? Well, again as we saw in the neo-Riemannian progressions chapter, third relations do not have to be diatonic. In some (both English and German-speaking) traditions the combined collection of possible mediants is divided into three categories as shown in the embedded example score-figure and sections below.
Grade 1 (a.k.a. Diatonic)
Grade 1, (also known as Diatonic) mediants share two common tones with the tonic and involve a change of chord quality type (between major and minor). For example:
- The R-relation connects C-major and A-minor
- The L-relation connects C-major and E-minor
Please note that these terms (“L” or “Leading-Tone Exchange”, and “R” or Relative) are as typically seen in English-language music theory today. Despite that English-language tradition having its roots in German music theory (notably from Hugo Riemann from whom “Neo-Riemannian” theory takes its name), contemporary German music theory would typically discuss these relations with the terms Gegenklang (G) and Parallel (P). This gets confusing, so please see the section on “Function and Transformations” at the end of this chapter. For now, we’ll stick with the “LPR” terms used so far (in the previous chapter).
Grade 2 (a.k.a. Chromatic)
Grade 2 (a.k.a. Chromatic) mediants are a step more remote. Here there is one common tone with the tonic and major or minor chord quality is the same in both chords. Some English-language sources give extra labels of Upper Flat, Upper Sharp, Lower Flat, and Lower Sharp to these four mediant types. Upper/lower refers to the root direction, and flat/sharp clarifies whether the third is major or minor (and typically corresponds to flat / sharp chords). For instance, C-major connects to
- Eb-major as the Upper Flat mediant.
- E-major as the Upper Sharp mediant.
- Ab-major as the Lower Flat, and
- A-major as the Lower Sharp.
(German-speaking theory accounts for these with function-transformational terms like Tonikavariant-Parallel).
Grade 3 (a.k.a. Disjunct, Doubly-Chromatic), and summary
In the third and last type, we still have median (roots-by-third) relations, but no common tones. The major/minor quality also changes. Given these changes (especially the