I’ve been following Brian Eno’s works about generative art for years, always being fascinated - I don’t know why -  by random or complex structures generated by “seeds” or “simple rules”.

Examples of this technic are “It’s gonna rain” by Steve Reich or “Music for airport” by Brian Eno (even if they are different in some respects), where a bunch of “rules” activate an evolving process with unpredictable results.

I’ve ever thinking to experiment this field and finally I decided to start a generative project sending a call for submission to the CT-Collective group.

The idea behind this project was to set predefined rules to get automatically mixed the contributor’s audio clips.

The first ...unpredicted result was the high number of artists interested in taking part in it. Due to this fact, I had to split the project in two subproject.

I asked for audio clips containing sparse notes, field recordings, short melodies or textures, that would mix automatically, just setting some “rules” to get starting an evolving process.

The generative process is based on “shift phase”, meaning that the clips’ different lenght produces different crosspoints between the layered clips while the execution goes on.

Also “patterns” play and mute (don’t stop, they’re just silenced) alternatively, and some musical clips alternatively change their pitch.

In the two long pieces resulting from this process, combinations of sounds are generate just for one time, meaning that and you’ll never hear the same combination twice.

Apart technical details and on a different level, the final results of both projects seems also to be musical,  even if it’s clearly: “background music”.


The interesting part of the work was to establish “rules” for layers of sounds I didn’t have listen to. I had to think to something that would work with many unknown sounds and musical fragments (11 clips in each project) giving a musical interaction.

Here are the “basic rules” I establish, followed by a brief description on how the generative process works in each project.

Clips duration:  00,37”-1,57” (project I)

                             00,47 -1,53   (project II)

Sounds:              field recordings, sparse notes, short melodies or textures

                             musical parts must be played with a single instrument;

                             each clip must contains “silent points” (pause).

Tonality:            C major

The Generative process

I thought to apply the generative process for composition, either for listening.


Shift phase” is the main rule in both projects.

Clips start playing one after another, so it’s easy keeping trace of each new sound that’s fading into the song. They fade out the same way, one after another.

Each clip is looped, but first loop plays, second loop is muted and so on. This is a “pattern”. After all patterns are started, they’ll start to mix automatically, and this mix will change over time, due the different lengths of each patters and combination of sounds given by the patterns that are playing or muting.

On CT-Generative II, works also are some other “rules”. In particular, after 3 patterns (six loops total - odd loops are audible, even loops are muted) the 4th is totally muted (loops #7,8 aren’t audible and so on...). All clips follow this rule from beginning to the end.

In some clips with musical content there is also a pitch variations (I-III; I-IV; I-V) that works just on alternate “even patterns” (2nd patterns play a pitch variation; 4th cycle is muted; 6th cycle plays a pitch variation; 8th cycle is muted and so on...).

Each clip plays for a fixed cycles number, then it stops.


The final mixes of both generative projects contain “track marks”. In each one I’ve put those marks where it was possible (this is the mainly reason I established the “silent points” rule and muted odd loops).

CT-Generative I has 40 track marks, CT-Generative II, has 34.

The mix was burned as “once” (no silence between the tracks).

You can listening to them as a unique long track or setting “shuffle” or “ramdom” fuction in your player, to get the sequences playing every time in a different order.

The Generative Room shows a digital version of this work, where you can make your own mix of the original projects’ clips.

Fabio Anile, January 2009