The Pentatonic Asylum (VCV Rack, Generative)

This is a long electronic piece created entirely with VCV Rack. It's generative in the sense that, except in the first one or two minutes, there is no manual interaction with the modules during the whole piece, and that many random elements in the setup provide enough variation so that every performance and recording is different.

While there is a lot of randomization, there are also controlled automated progressions that give the piece a recognizable structure and overall architecture:

- First of all, the harmonic progression is a stepwise walk through the circle of fifths. Each step selects the respective minor pentatonic scale, starting from a-minor, then e-minor, b-minor, f#-minor, and so on. This goes five times through the twelve notes of the circle of fifths.

- The "steps" do not always have the same length. The minimum step length is about 50 seconds but there is a chance (of 60%) that the modulation to the next scale will be delayed by another minimum step length, and this can repeat. So, sometimes the music can stay in the same scale for many minutes before it shifts to the next pentatonic scale.

- Each shift to a new root note is introduced by a clear pattern:
--- A single "ping" (like a triangle) of the new root note in a high octave
--- Then a sequence of two chords of the minor triad (sounds a bit like an e-piano), echoed twice with decreasing loudness
--- Then, and overlapping with those chord echoes, a long crescending and descrescending chord of all five notes of the minor pentatonic scale

- Each step changes multiple probability parameters for various voices of the piece. The change of probabilities is not random but strictly sequenced in a way that the voices follow a wave-like pattern from being entirely absent to very active and prominent, and back again.

- The probability sequences per voice have different lengths (between 8 and 16 steps) so that their maxima and minima do not always have the same distance to each other. In other words, two voices can be completely absent at the same time, or they can both be very prominent, or only one of them, and everything in between.

- This effect is amplified by the probability sequences having independent chances to change their direction.

- The three arpeggiators can run alone, or together in all combinations, or not at all.

- The first about eight steps are rather forced, just to introduce all voices once step by step, before it becomes more random, and all kinds of voice combinations and probabilities can occur.

- When the five cycles through the twelve scales are finished (so, after 60 steps), the patch switches into a kind of fade-out mode. This can still take several additional steps and minutes, but voices that have disappeared once do not return again in this mode. In addition, the announcement of a new scale is reduced to the ping signal only. The step length of a scale is forced to be the minimum length. The patch is slowly silencing and fading out itself, so to speak.


The piece has 16 voices in total. Aside from the mentioned three voices that underline the theme of the pentatonic circle, they can be divided into three groups:

- Ambient support: Two quiet pad voices that are always present to provide an ambient bed for the whole piece. A guitar and bass guitar sound. Due to their long decays they rather emphasize the pad voices and reinforce the ambient background than standing on their own. A bass synth that pushes a deep slow wave through the ambience every now and then. An occasional noise that pans between left and right and sounds a bit like birds (or big insects?) fluttering through the scene. A regularly occuring but varying sequence of chimes to add a few grains of salt to the ambient mix.

- Lead voices: A flute-like and two synth voices. Especially the second one is very much in the foreground and could be perceived as a main voice if it's playing, which is not always the case. The first one sounds kind of suppressed as if it doesn't dare to fully enter the stage, except when it's playing alone, then it unfolds some interesting sound modulations.

- Arpeggiated patterns: There are three arpeggio voices, one with a simple sequence of the five notes of the scale going either up or down, a second one that plays in a relaxed swing, up or down or pendulum, and the third one is in a more vibrant dance mood and sometimes jumping an octave up or down.


This is the largest and most complex patch I made so far. Most of it is already a few months old. I refrained from the hassle to record and edit a full and huge video of the running patch. So, I decided to show only a brief sequence of the patch at the beginning (not in sync with the audio because the video snippet and the full audio are recorded separately), and then switch to a very simple animated, repeating and not very exciting video (images generated, and the animation fiddled into the images by me afterwards).