Generative Algorithm – Simple Pitch

Simple Pitch

This post is documentation of practical research done with one of the max patches I have built to generate melodic content within Ableton. My aim is to show what results this specific system allows for, and in later posts I will use a combination of systems in parallel to generate a “finalised” harmonic piece. I chose to showcase these algorithms with a very simple synth sound without any modulation, so that the harmonic content is as clear as possible. Please note that the algorithm generates fully chromatic notes that are, in a separate module, restricted to play within a specified scale in order to comply with the easily accessible aesthetic I wish for my installation to have.

This system is the current version of a long development process, that has increased in complexity and possibilities over its creation. It is based on the first algorithm I attempted to create, and has thus been developed from not working at all, to being able to generate usable content based on five equal algorithms, one per instance of dripping/trigger. To explain the interface, one can find the following functions, from top to bottom:

On/Off: Allows to use/ignore the trigger from each of the drips. Useful if you only want to create notes from a few specific drips
Interval: Allows notes to be played at a set interval of drips. A setting of 0 plays a note at every drip, a setting of 19 plays a note at every 20th drip.
Set Note: If the button below this note number is set to “Steady”, this note will be played every time a drip is triggered.
Steady/Random: If set to “Steady”, the device functions as described above, if set to “Random” the algorithm plays a random note within the high/low note range specified below the button.
High/Low: Range for the randomisation as described above.
Note output: This box is updated at every played note, to give a visual representation of which instance is playing what.
Velocity & Duration: Allows to specify individual note velocity and duration for each of the instances. Useful to create a dynamic melody line

Set Pitches

With this setup, each of the five falling drops trigger a specified, individual note. The result is very simple, and easy to follow. There is a sense of minimalism, as melody lines start emerging and dissolving, as the notes are shifting order depending on the speed of the different dripping rates. Only using five notes, without any melodic or sonic modulation, does quite quickly become static and uninteresting, and further experimentation is needed in order to keep the listener in a sense of natural evolution.

Fully Random

Randomising a full range of reasonable pitches on all five triggers gives a very sporadically interesting result. This is providing the widest pitch indeterminacy possible within the system. At times the unpredictability works beautifully, however at times the immersive/intuitive mood that builds up by the system is broken by playing notes that are too unpredictable. A combination of steady pitches and some random ones could provide a controlled, stable foundation while adding a layer of unpredictability that allows the listener to be continuously surprised or intrigued. The fully randomised system is very unpredictable, but there is a sense of stability in the continuous indecisiveness.

Combined Set and Random

A combination of the two systems mentioned above produces a slightly less stable set of notes than the fully steady system, yet more useable than the completely randomised system. Small variations note constraints for the randomisation can produce great improvement in creating a sense of direction in the creation of melodic themes. The first example of this method uses a wide randomisation (C2-C5) on two of the triggers, which, in comparison to the all set notes, lacks a sense of direction or decisiveness.

Combined, Constrained

The second example using this system uses the same two triggers for randomisation, but restricts them to only play variations in the higher range of notes (F4-F5), which enables a sense of melodic content to be created, while a foundation of a chord is supporting this unpredictability. When used in this fashion, there is potential for building structures where the root chord is changing, creating harmonic development.

Constrained Random

By constraining the possible randomisation amount to only a few semitones, one can produce a melodic result that is similar to the one of steady pitches, yet slightly indecisive in a way that occasionally produces unpredictable melodic motifs. This approach could be useful for generating simple melodic lines that keeps some level of direction, but sways back and forth in how how rigid the content feels. The result is similar to a human player who knows what keys are in a scale, but is not sure how to put the notes together to produce a strong melodic line.