Ensemble interaction in indeterminate music: A case study of Christian Wolff’s Exercises

Examining ensemble interaction in the music of experimental composer Christian Wolff, this chapter uses as a case study a professional recording session undertaken by the ensemble Apartment House of <em>Exercises</em> (1973–2013), a series of pieces for (mostly) unspecified instrumentation and numbers of players. Wolff’s skeletal notation is deliberately under-determined, acting like something of a puzzle to be solved. Consequently, the players must negotiate a way of working with the notation and with each other, making decisions prior to, and during, the moment of performance. Drawing on interviews and observational studies, the chapter identifies three different forms of interaction in the musicians’ playing as they engaged with Wolff’s notation: working responsively, independently, and emergently. The chapter offers a view of ensemble interaction that is characterized by cooperation, but also uncertainty, surprise, or even complete breakdown.