An Orchestra Faces the Test of Indeterminacy

This article examines the collaboration between ONCEIM—an orchestra made up of about thirty musicians specialised in musical improvisation —and the pianist and improviser John Tilbury, from whom ONCEIM commissioned a piece entitled Sans. This process of musical creation was remarkable in that all participants had to work with a high degree of uncertainty regarding the nature of the project and, therefore, the distribution of roles and creative authority. This uncertainty permeated all aspects of the collaborative work that led up to the first public performance of Sans. The present paper is based on an ethnographic study of all the rehearsals John Tilbury and ONCEIM held together, as well as on semi-directed interviews conducted with various orchestra members. We first illustrate the deep ambivalence of John Tilbury’s attitude and preliminary instructions to the orchestra, which oscillated between two regulating approaches to musical activity. Next, we examine the various “prescriptive impulses” of some members of ONCEIM, which sought to fill the “vacuum of power” left by John Tilbury. Finally, within this largely indeterminate context of interaction, we show how musicians based their musical choices on deontic as well as organizational criteria.