Orchestral Voicings Part 9: Cluster Voicings

In the last parts we were already dissolving the common concept of stacking thirds in order to get a chord. In the last part we were having a look at intervals larger than a third so it seems consequent to look at intervals smaller than a third, which, effectively are only minor and major seconds.

This is where we crossover to a musical device called "cluster", which essentially are a block of several notes that are a minor or major second apart from each other played simultaneously. However we need to distinguish here. The device that is called cluster usually stands for an effect that doesn't serve much of a harmonic function. It is a textural device that serves to create a certain blurry pitch impression or create a textural wall. With cluster voicings however, we can still serve a harmonic purpose as these clusters can in fact be diatonic and therefore imply a certain scale that can imply a harmonic function.

For instance lets take this diatonic cluster:

https://soundcloud.com/robin-hoffmann/lydian_cluster/s-uE9eWhLL2vH

In its form it very clearly implies a lydian scale with its 3 stacked major seconds and one minor second. Depending on what bass note I give it, it can serve as an F(#11) chord (with bass note F), or a sort of Dm (with D in Bass) or even create a Gsus4 feeling (with G in the Bass). In any case it serves a harmonic function. Yet, due to its dense structure it feels very compact and "rubby" and implies quite a bit of dissonance in spite of the lydian feel.

Again, as with fourths and fifth based chords, that structural element of seconds doesn't need to be the exclusive property of the voicing but in order to create the desired effect should be the dominating property.

Here's an example where I constructed voicings out of fourths and seconds with the cluster sound dominating due to its position in the voicing:

https://soundcloud.com/robin-hoffmann/fourths-and-seconds/s-51bFFRGj47J

There is a technique in modern big band arrangement, where instead of harmonizing a melody with regular chord voicings you harmonize it with cluster voicings. This of course results in a quite dense and colourful melodic impression as well as clouding the melodic main line (if you don't double it accordingly).

Another strategy to use such voicings is to create a dramaturgic ark over a chord progression. In the example below, I start of with an open fifth sound that gradually tightens up towards the cluster voicing peak in bar 5 and gradually relaxes back to a fifth voicing in the remaining bars. The top line follows that same dramaturgy but wouldn't necessarily need to. 

https://soundcloud.com/robin-hoffmann/cluster_progression/s-8nqdsAD2BCc

Of course, this example is a little clumsy and just a quick sketch to illustrate the concept. In a more artful way you wouldn't construct it as "on the nose" as this one and it makes incredibly more sense to stretch such a conceptual idea out over a longer period as well as not slavishly following that idea all the time if a more musical side step seems more appropriate but it shows that you can use a cluster voicing as a dramatic peak of a chord progression and even more elegantly if you develop towards it. Of course you should consider a cluster voicing as a "full measure" device, there is hardly a chance to prevent it from developing a rather painful dissonance but in the right context it might work really well.

Of course, cluster voicings don't need to be diatonic but even if you construct symmetrical clusters (e.g. only whole steps, or half-whole steps alternating), they start to imply a certain scale. The intensity of the cluster voicing can be controled by the amount of notes that you employ. However be aware that clusters tend to eliminate any transparency of the underlying structure especially when you stretch them out over a larger range.

Also, low interval limits apply to them, so don't expect any harmonic implication from a diatonic cluster that you place too low.

The least musical information are clusters that consists mainly out of minor seconds. They create the highest degree of dissonance and basically no harmonic information. So don't expect them to function as a chord placeholder.

You may have noticed that the further we progress in this tutorial series the more we deal with rather strong dissonances which might scare off a few people. After all, why would you want to write music that has such a high degree of dissonance that it will not be suitable anymore for the average listener (unless you need to score a murder scene or something similar). This is where we will pick up in the next part, where we will talk about the management of dissonances and what an essential role they play in music.