The CEG Algorithm (Part I)

  • Elaine ChewEmail author
Part of the International Series in Operations Research & Management Science book series (ISOR, volume 204)


This chapter presents the Center of Effect Generator (CEG) key-finding algorithm based on the Spiral Array model, starting from the idea of the center of effect (CE), whereby any sequence of notes maps to a point in the interior of the model. The algorithm is illustrated through a simple melodic example, “Simple Gifts” from Copland’s Appalachian Spring. Included are discussions on why the model works, and the principles behind the particular set of model parameters used in the test run. At each step, the algorithm reports the three closest keys, ranked by distance; a step-by-step geometric interpretation of the algorithm and a graph showing the evolution of the closest keys accompany the tabular results. A MATLAB version of the CEG code appears in Appendix B. An evaluation of the CEG algorithm follows in Chap.  5; the CEG method is applied to polyphonic music in MIDI (Musical Instrument Digital Interface) format in Chap.  9, and adapted to music audio in Chap.  11.


Pitch Collection Duration Information Musical Instrument Digital Interface Pitch Position Polyphonic Music 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Centre for Digital MusicQueen Mary University of LondonLondonUK

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