Algorithmic Composition With Python

1. Algorithmic Composition With Python

Dr. Hendrik Niemeyer

2. What is Neue Musik

• Moving away from traditional harmony and form and exploring
dissonant sounds, experimental techniques and unexpected
structures
• Experience music as art
• Challenging traditional listening habits
• Emancipation of dissonance
Dr. Hendrik Niemeyer - ROSEN Technology and Research Center GmbH
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3. Contemporary composers

• John Cage: Known for his experimental approaches
• Philip Glass: A key figure in minimalism
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4. History of Algorithmic composition

• First composition recipes based on throwing dice in the 18th century
• Results of throwing multiple dice are used to look up a bar of music
in a table
• Usually used for periodic forms of music like waltzes, polonaises, or
minuets with a highly schematic harmonic structure
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5. History of algorithmic composition

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6. Lets Play a Musical Dice Game

• https://dice.humdrum.org/
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7. History Of Algorithmic Composition

• Lejaran Hiller (1956): “The Illiac Suite for String Quartet” uses Markov
chains and random walks
• Iannis Xenakis (1964): „Eonta“ uses Brownian Motion
• Gerhard E. Winkler (1996): „Hybrid II Networks“ uses neural networks
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8. What can we Produce?

Score
MIDI
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Sound
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9. What is Midi?

• Technical standard for storing and communicating musical events
• E.g. pitch, timing and velocity of a note
• A MIDI file contains no sound (you need virtual instruments like a
synthesizer to create sound)
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10.

Music Theory
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11. Scientific Pitch Notation

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12. Intervals

Open Music Theory
• https://viva.pressbooks.pub/openm
usictheory/
• Authors: Mark Gotham; Kyle
Gullings; Chelsey Hamm; Bryn
Hughes; Brian Jarvis; Megan
Lavengood; and John Peterson
• License:
https://creativecommons.org/licens
es/by-sa/4.0/
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13. Intervals

Note Values
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14. Open Music Theory

Diatonic Chords in Major
ii-V-I
I-V-vi-IV
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15. Note Values

Links To Music21
• https://music21-mit.blogspot.com/
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16. Triads

Music21
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17. Scales

Note Object
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18. Diatonic Chords in Major

Scales
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19. Chord Progressions

Stream Object
• Stream object is a container for generic musical objects
• Basic building block of music21 package
• Unlike a list more than one object can be placed at the same position
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20. Links To Music21

Score And Part
stream.Score
Whole piece of
music
stream.Part
A single
instrument
stream.Voice
A melodic line
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21. Music21

Score and Part
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22. Note Object

Score and Part
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23. Scales

Chords
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24. Stream Object

Chords
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25. Score And Part

Chords from Text
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26. Score and Part

Chords from Text
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27. Score and Part

Our
Compositons
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28. Chords

Composition: Random Walk
• Stochastic process
• describes a path that consists of a
succession of random steps
• E.g. in 1D position + 1 with p=0.5
and position -1 with p=0.5
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29. Chords

Composition: Random Walk
• Melody is generated by mapping a random walk onto a C Major
scale
• Note length is drawn at random as well
• Simple harmonic structure from I-V-vi-IV chord progression
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30. Chords from Text

Composition: Random Walk
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31. Chords from Text

Composition: Random Walk
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32.

Composition: Random Walk
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33. Composition: Random Walk

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34. Composition: Random Walk

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35. Composition: Random Walk

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36. Composition: Random Walk

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37. Composition: Random Walk

Further Ideas
• Accompaniment could be made random as well
• Combine multiple random walks for a polyphonic texture instead of
melody + accompaniment
• Creativity is limitless
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38. Composition: Random Walk

OEIS
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39. Composition: Random Walk

Composition: Listen To OEIS
• Online Encyclopedia of Integer Sequences
• Choose an arbitrary sequence and turn it into music deterministically
• Chordal texture
• Use number to choose pitch, chord type and duration
• „atonal“ music
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40. Composition: Random Walk

Composition: Listen To OEIS
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41. Composition: Random Walk

Composition: Listen To OEIS A000010
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42. Further Ideas

Composition: Listen To OEIS Primes
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43. OEIS

Other OEIS music
• https://oeis.org/play.html
• https://github.com/tom111/oeistools
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44. Composition: Listen To OEIS

Alternative Packages
• https://abjad.github.io/
• https://mido.readthedocs.io/en/stable/
• https://github.com/georgesdimitrov/arvo
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45. Composition: Listen To OEIS

Literature
• Book: Music Theory for the 21st-Century Classroom
• Music21 Docs
• Procedural music composition with Python
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46. Composition: Listen To OEIS A000010

Questions?
Dr. Hendrik Niemeyer
ROSEN Technology and Research Center GmbH
E-Mail: hniemeyer@rosen-group.com
Mastodon: @hniemeyer@mastodon.social
Bluesky: @hniemeyer.bsky.social
LinkedIn: https://www.linkedin.com/in/hniemeyer87/