MATHEMATICS AND GROUP THEORY IN MUSIC ATHANASE PAPADOPOULOS Abstract. The purpose of this paper is to show through particular examples how group theory is used in music. The examples are chosen from the theoret- ical work and from the compositions of Olivier Messiaen (1908-1992), one of the most influential twentieth century composers and pedagogues. Messiaen consciously used mathematical concepts derived from symmetry and groups, in his teaching and in his compositions. Before dwelling on this, I will give a quick overview of the relation between mathematics and music. This will put the discussion on symmetry and group theory in music in a broader context and it will provide the reader of this handbook some background and some motivation for the subject. The relation between mathematics and music, dur- ing more than two millennia, was lively, widespread, and extremely enriching for both domains. 2000 Mathematics Subject Classification: 00A65 Keywords and Phrases: Group theory, mathematics and music, Greek music, non-retrogradable rhythm, symmetrical permutation, mode of limited trans- position, Pythagoras, Olivier Messiaen. This paper will appear in the Handbook of Group actions, vol. II (ed. L. Ji, A. Papadopoulos and S.-T. Yau), Higher Eucation Press and International Press. The author acknowledges support from the Erwin Schr¨odinger International Institute for Mathematical Physics (Vienna). The work was also funded by GREAM (Groupe de Recherches Exp´erimentales sur l’Acte Musical ; Labex de l’Universit´ede Strasbourg), 5, all´ee du G´en´eral Rouvillois CS 50008 67083 Strasbourg Cedex. Email:
[email protected] 1. introduction Mathematics is the sister as well as the servant of the arts.