How To Control Chaos in Music Production: A Conversation with XILS-lab

In the evolving landscape of electronic music, chaos has become a creative principle, not just a happy accident.

The French software company XILS-lab has captured this energy in KaoX, a virtual instrument that fuses the mathematical precision of FM synthesis with the unpredictability of chaotic modulation. Inspired by the groundbreaking FM synthesizers of the 1980s (the same digital machines that redefined pop and experimental sound design alike) KaoX reimagines their legacy for the DAW-driven producer of today.

At its core, KaoX is an experiment in control and surrender. Its dual-layer architecture and “chaos modulators” allow sound designers to push texture and tone to their breaking points – creating timbres that evolve, destabilize, and reform in real time. At first, you may think that this sort of feature would be too unstable to use in practical music production. But, XILS-lab has found a way to truly harness it with KaoX, and have turned chaos from something unpredictable and erratic to a force for creativity.

We sat down with Xavier from XILS-lab to learn a bit more about how chaos is generated within KaoX, and how you, too, can harness it to take your productions to new heights.

How do you define “chaos” in the context of sound synthesis, and why was it so important to implement chaos into KaoX? 

In the nature, chaos is everywhere. Wind, bird songs, rain, clouds but also the flow of air in a wind instrument, the movement of a bow on a string. For avoiding a static and cold FM-like synthesizer, the idea of adding some sort of chaos sounded obvious for me.

In what way do the chaos oscillators differ from traditional FM or analog oscillators in KaoX?

A simple FM synthesizer can be quite cold, so we decided to allow chaotic oscillators to modulate some of the FM parameters. This way, the sound is never exactly the same, but keeps its character. On each operator, there is a way to choose any modulation source, including the chaos oscillators. Also, using directly the chaos oscillator as a sub oscillator for instance, can bring a lot of life in a sound.

Can you explain how chaos is mathematically or algorithmically generated inside KaoX?

There are three algorithms so far. Two are standard chaotic algorithms, Lorenz and Rossler, which give a circular movement like a simple LFO (but this circle is never exactly the same), and a third algorithm, created with two-mass lip-like movement oscillating under airflow.

For instance the Rössler algorithm is done by calculating the variation on the tree axis, dx = -y -z, dy = x+ay and dz= b+z*(x-c). The a, b and c parameters allows to change the movement in this 3-dimensional space. For KaoX, we just pick up one of the values, x or y, using as an oscillator. 

How can sound designers harness this chaos without losing control of their work?

A chaotic moment is not random, so when an FM operator is modulated by a chaotic algorithm, it’s almost the same as being modulated by a LFO. The difference is that the circles are not static, always changing in frequency, but the amplitude keeps a sort of pattern.

What are some creative ways that you’ve seen people use chaos in KaoX?

For instance, in the KaoX factory presets, sound designers use the chaotic oscillators for adding high frequency components, keeping the sound always moving. This doesn’t change the pitch but adds something really interesting. 

Do you see the chaos section as more of a subtle enhancer or a core creative tool for users?

When the sound you are after is more like a sound of nature (thunder, bird call, wind, etc ..) then using a chaotic oscillator can be very useful. 

Lastly, do you think chaos-based modulation will become more common in future VSTs?

I think that if not directly integrating chaos, a lot of synthesizers are offering ways for sound designers to generate chaos (for instance two or three LFOs modulating each other). Sounds designers want life and natural elements in their sounds, so having direct access to chaotic algorithms helps them reach their goals.

KaoX is currently on sale for 50 Euro. Grab it here!