Contents
4. Theory of the Mixolydian Mode
Now, let’s summarize the use of chords in four categories as before.
Neutral Chords
Those that are unaltered from the state of the major key are referred to as “neutral chords”.
The chords that Mixolydian mode shares with the major key are these four. I is, of course, overwhelmingly used, followed by IV.
On the other hand, IIm and VIm are not frequently used. There are several reasons for this. Firstly, these minor chords do not quite match the character of the Mixolydian mode, which is bold and bright. Additionally, VIm creates a strong dissonance between the root note la and the characteristic note ti♭, making their combination less favorable.
Character Chords
The characteristic note of the Mixolydian mode is the flattened seventh degree. The chords that include this note (and can be practically used) are referred to as “character chords.” In the Mixolydian mode, there are two character chords.
Both are commonly used, but 
VII is more versatile. Mixolydian mode compositions often come together by simply repeating I and VII.
Using overly clever chords can diminish the Mixolydian mode’s inherent “boldness”, so it’s better not to complicate things unnecessarily.
Foreign Chords
Chords that become less usable due to the character note are termed “foreign chords”. Mixolydian mode has one foreign chord.
It’s this one. This unstable harmony significantly detracts from the “bold and bright” atmosphere of Mixolydian… I haven’t seen it used.
Auxiliary Chords
Chords that include notes outside of the mode but are practically useful in creating chord progressions are referred to as “auxiliary chords”. In the Mixolydian mode, there are two chords that seem to meet this condition.
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p>III and VI chords, borrowed from the C minor key. As Mixolydian itself introduces a parallel minor sound with ti♭, incorporating these similar parallel minor chords naturally expands the range of expression.
So, I and VII are the basics, and you can optionally use IV and Vm. This is more than enough to navigate the world of the Mixolydian mode.
Pop/Rock Control
As mentioned earlier, a mixolydian mode can easily retain its modal tonic unless you intentionally design an ambiguous chord progression. Any melodic lines may work fine. However, note that depending on the lines you choose, the direction can significantly shift between a merry pop feel and a robust rock vibe.
Rock Feel
As you’ve already seen, using common tones with the minor scale like (do, fa, so, ti♭) gives it a more minor feel, leading to a sense of power.
This is a song by a famous rock band, Deep Purple. It extensively uses the Mixolydian mode. In the A section, it revolves around so, ti♭ and do, with no appearance of mi, creating a powerful sound between major and minor.
Pop Feel
On the other hand, the area “ti♭-do–re–mi” is quite distinctive, maintaining a whole-step throughout. This contributes to the “unusual brightness” of the song. In the case of the major scale, a sequence of whole-steps occurs in the fa to ti interval. However, since the endpoints, fa and ti, are strong tendency tones pulling outward, it’s quite rare to construct a line centered around these four notes.
Especially on the I chord, it is challenging to utilize them. Therefore, in major scale music, the “three consecutive whole-steps” rarely play a prominent role. However, in the case of the Mixolydian mode, the notes “ti♭-do–re–mi” function as a well-balanced group.
Ti♭ can naturally form an ascending resolution to the tonal center. Additionally, mi is a weak tendency tone (and also a symbol of the major quality). Therefore, crafting melodies on the I chord using these four notes is a standard composition in the Mixolydian mode.
When this “consecutive whole-steps” prominently appear, it leads to an unfamiliar and peculiar pop sensation. For example, a phrase like “ti♭-do–mi” contains typical character of the Mixolydian mode such as the whole-step resolution, brightness of mi and a scent of tritone interval made between ti♭ and mi.
This is a track by Kraftwerk, the techno pioneer. The main phrase in this song is “ti♭-do, mi–fa–mi”, resulting in a quite peculiar sound.
By paying attention to the differences in phrasing between “rock-style Mixolydian” and “pop-style Mixolydian”, you can avoid situations like, “I tried to create a bold rock melody, but it turned into a strangely pop-like sound…”
The Mixolydian mode can be used throughout the entire song or selectively in specific parts. Having the folk-like Dorian mode and the merry & bold Mixolydian mode as options will further expand the possibilities in songwriting.
Summary
- Similar to the Dorian mode, the Mixolydian mode has a high affinity with popular music.
- Mixolydian is created by lowering the seventh note of the major scale by a half-step, bringing strength and boldness.
- Mixolydian is a scale situated between major and minor, with the frequency of the third note significantly influencing brightness.
