Eurorack users often find that their patches can take on a life of their own, and this is actually one of the goals in the creation of generative patches. Generative patches, or generative music, is the concept of connecting your modules in such a way that they basically play themselves with little or no interaction from the user, yet the music evolves and changes without repeating itself. This is sometimes also referred to as Procedurally Generated Music, and it is something that modular synthesizers and computer programs are uniquely qualified to do. In fact, the term was originally coined (not surprisingly) by Brian Eno while working with software. He used this term to describe “any music that is ever-different and changing, created by a system”. The approaches to generative music can be almost as varied as the results, but there are a few ingredients and techniques that are essential.
Here’s a little generative patch I cooked up using Make Noise Wogglebug and Maths, MFB Kraftzwerg, Mutable Clouds, and Intellijel Rainmaker:
When you make a generative patch, you are basically setting up a system that will interact with itself with little to no outside manipulation. To do this you need to define the actions and reactions that will propel things, and determine the range and flow of values that will make it evolve. Probably the most commonly used and critical component to facilitate both tasks is the function, or envelope generator.
However, it really helps if it is a function generator that sends gates as well as receiving them. For example, probably the most famous function generator is Make Noise Maths, which has a gate output for End of Rise on one side, and End of Cycle on the other. Intellijel’s Quadra Expander provides end of cycle trigger outputs for each of the four functions, so you can set up complex cascading modulations from one place. The Pingable Envelope Generator from 4MS has both end of rise and end of fall trigger outputs.
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