Canon-generator: algorithmic composition using music21, scamp, abjad and python

• Written by Stefaan Himpe - 2013
• Revised to use python 3.8 and music21 6.3.0 - 2020 NOTE: canon-generator now also depends on the scamp library to generate the final notation

Code available under GPLv3.

Simple tonal canon generator. The main function contains some parameters that can be edited by the user (for now, no UI/command line options available).

chords = "C F Am Dm G C"

• You can insert a new chord progression here.

scale = music21.scale.MajorScale("C")

• You can define a new scale in which the notes of the chords should be interpreted here

voices = 5

• Define the number of voices in your canon here

quarterLength = 2

• Define the length of the notes used to realize the chord progression (don't choose them too short, since the automatic spicing-up will make them shorter)

spice_depth = 1

• Define how many times a stream (recursively) should be spiced up, e.g. setting 2 will first spice up the chords, then again spice up the already spiced chords. Scores very quickly become rhytmically very complex for settings > 2

stacking = 1

• the code can generate multiple versions of the spiced up chord progression, and use those versions to create extra voices. E.g. setting stacking = 2 will turn a 3-voice canon into a 3*2 = 6-voice canon

voice_transpositions = { VOICE1 : +12, VOICE2 : 0, VOICE3 : -12, VOICE4: -24, VOICE5: 0 }

• allow extra octave jumps between voices