algorithmic composition

This patch provides an example of simple interactive improvising program that plays a melody influenced by the notes played by a live performer. Based on the most recently received MIDI note, the program chooses a scale to use for its melody, and moves melodically in a straight line toward the pitch and velocity most recently received. The program has only one use of randomness, to make a probabilistic decision. It has a small musical knowledgebase of three scales, and a set of probabilities determining which scale is more appropriate for use at any time.

This patch shows an idea for an automated improvising algorithm. At regular intervals of time, which one might think of as the length of a musical phrase (every 1.6 seconds in this example), the metro object chooses a new random number from 0 to 35. That number will be considered a target number toward which the line object should go.

Analog synthesizers of the early 1970s often included a "sequencer" capable of cycling through a timed sequence of 16 different voltages (which would most commonly be used to control the pitch of an oscillator). This likely explains why so many fast 16-note repeating patterns appeared in electronic music of that time period. Most voltage sequencers allowed the user to set the voltage for each step of the sequence, and to adjust the timing interval (rate) of the sequence.