In this post I will be showing you different ways of using tonal and chromatic polychord structures in your music. But first, a thing or two about polychords. It consists of two or more chords played together and such chords may be originated from the same or different tonalities – usually the latter is applied.
Generally, the chords that make up the polychord must be perceived independently, although it is not mandatory. Nevertheless, when the chord pitches are mixed, the overall chord structure will be considered as one complex unit:
Normally, if you want the individual chord formations to be heard distinctly, they should be properly spaced since depending on the way that the involved chord notes are arranged, more or less tension can be created.
When polychords are built from chords in the same tonality, they can be considered, in fact, as chord extensions. As an example, if you have a C and a G major chord from C major tonality, you can either represent it as a C|G or Cmaj9:
Using Scales With Polychords
If you want to make melodies over polychords, and if the case is like the example above where we built a polychord with chords from the same tonality; then it is quite straightforward as you are not implying another tonality and the notes used in each chord belong to that tonality. As said, you will be hearing this polychord as a chord extension based on the tonality you are using.
In polychords built with chords from different tonalities, you can either use a compound scale made with the notes of those chords or you can go back and forth from the implied tonalities.
Polychords in Context
The following example uses mostly polychords from the same tonality. Notice how more familiar and consonant these chord structures may sound to you:
Although the Bb+ chord isn’t part of the Db major tonality, I used it to resolve to Ebm in the polychord’s upper structure
Keep in mind that the relative distance of the tonalities you are using to build the polychords will have an impact on how the polychord sounds. Think about it as the choice of key relationships and how dissonant or consonant they will sound when the respective chords are juxtaposed.
A consonant relationship is considered when you are using chords from a tonality that has at least five common pitches – i.e. C major and F major or C major and D major. And a dissonant relationship occurs when less than five common pitches are shared between tonalities – i.e. C major and Ab major.
Another way of using polychord structures is to use the upper structure with the same chord while you use the lower structure to change the colour of the polychord:
The polychords from the last four bars are built based on the descending chromatic bassline
This last example uses another way of thinking about building polychord structures. In this case, I’m using a more static chord succession in the lower structure that is maintained throughout, in a similar approach to modal harmony. The upper structure has more harmonic movement and closer to a tonal chord progression.
I built the polychords in a way that the respective upper and lower structures confirmed the tonal or modal centres they belong to – In D major (for the upper structure), and F Dorian from Eb major tonality (in the lower structure):
Again, the F+ chord that appears in the upper structure isn’t part of the Eb major tonality and is used to resolve back to D
Things to Consider When Working With Polychord Structures
- for the resonance of polychords, it is advisable to follow the logic of how the overtones are produced – open position voicing at the bottom and the other chord with close position voicing at the top:
- pay attention to where dissonant intervals are placed. The usage of dissonant or consonant intervals in the outer voicings of the chord structure determines its perception quality throughout the chord formation.
- as with clusters, some of the consonant or dissonant quality may be enhanced or dispelled according to how closely you place both chords; by the way you voice the chord structure and its register; by the way that the involved chord notes are presented; or by arpeggiating one or both chords
Any type of chord can be used to build a polychord but three note chords are usually more common. However, the decision of the chord quality and their extensions and the techniques you use to make and present polychords are entirely up to you.
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