What do we mean “Generative” music?
Generative
Generative music is music (largely) created by a system, rather than played by a human. After a trigger event—like pressing ‘play,’ hitting a note, or sending a voltage in a modular synth—the system follows a set of rules, algorithms, or probabilities to generate and evolve musical ideas (notes, rhythms, timbres). In some cases the generative algorithms work with the performer, reacting to their input. In other cases the performer may intervene with the algorithms to tweak, adjust or change direction.
Generative music means (to me) that the music should be able to go on indefinitely, evolving over time rather than being simply repetitive.
In the context of generative ambient music, the goal is to have enough activity to be interesting, but not so much that any particular element “sticks out” and grabs the listener’s ear.
Some generative algorithms take parts that the performer plays and augments this with additional harmony, chords or (counter) melodies. An example of this is Olafur Arnalds’ and Halldór Eldjárn’s Stratus algorithm for performer pianos where MIDI triggers generate sequences of associated notes, chords and “ripples” in a separate instrument or player piano.
Other generative music involves complex algorithms, probability triggers and modulations to create ever-changing sounds, sequences, rhythms. Often these are programmed via modular synth rigs using LFOs, sequencers, quantizers, harmonic generators, bernoulli (probability) gates, Turing machines (random note and sequence generators).
It’s your choice what you do with these generative parts - either shorter, reactive sequences or long infinitely varying sequences. Through modulation and automation it’s possible to create music where the sounds evolve, appear, disappear, blend or create dissonance. In this book we’ll try to present some ideas that will help get you started on this journey. I recommend that you try out the ideas in practice. Let the sequences play. Sit with them for a while and let what you hear guide your next move. If you like parts of what you hear, save those as little self-contained ideas for use in other tracks. If you don’t like what you hear, then try replacing one or more parts and repeat the process of listening and refining. You can take the generative parts together to form a completely generative piece of music, or you can take only one element and build a track around that. Or you can take a snippet of one idea and use that as a kernel for new sound design, resampling it or reusing it in a completely structured and arranged piece of music.
This is a playground of choices - some you can make, and then some that are made within the generative processes.