Interactively evolving harmonies through functional scaffolding

Amy K. Hoover, Paul A. Szerlip, Kenneth O. Stanley

Research output: Chapter in Book/Report/Conference proceedingConference contribution

20 Scopus citations


While the real-time focus of today's automated accompaniment generators can benefit instrumentalists and vocalists in their practice, improvisation, or performance, an opportunity remains specifically to assist novice composers. This paper introduces a novel such approach based on evolutionary computation called functional scaffolding for musical composition (FSMC), which helps the user explore potential accompaniments for existing musical pieces, or scaffolds. The key idea is to produce accompaniment as a function of the scaffold, thereby inheriting from its inherent style and texture. To implement this idea, accompaniments are represented by a special type of neural network called a compositional pattern producing network (CPPN), which produces harmonies by elaborating on and exploiting regularities in pitches and rhythms found in the scaffold. This paper focuses on how inexperienced composers can personalize accompaniments by first choosing any MIDI scaffold, then selecting which parts (e.g. the piano, guitar, or bass guitar) the CPPN can hear, and finally customizing and refining the computer-generated accompaniment through an interactive process of selection and mutation of CPPNs called interactive evolutionary computation (IEC). The potential of this approach is demonstrated by following the evolution of a specific accompaniment and studying whether listeners appreciate the results.

Original languageEnglish (US)
Title of host publicationGenetic and Evolutionary Computation Conference, GECCO'11
Number of pages8
StatePublished - 2011
Externally publishedYes
Event13th Annual Genetic and Evolutionary Computation Conference, GECCO'11 - Dublin, Ireland
Duration: Jul 12 2011Jul 16 2011

Publication series

NameGenetic and Evolutionary Computation Conference, GECCO'11


Other13th Annual Genetic and Evolutionary Computation Conference, GECCO'11

All Science Journal Classification (ASJC) codes

  • Computational Theory and Mathematics
  • Theoretical Computer Science


  • Accompaniment generation
  • Compositional pattern producing networks (CPPNs)
  • Interactive evolutionary computation (IEC)
  • Music
  • NEAT


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