For most electroacoustic composers, ‘interactivity' refers to technology which responds to input from a performer. For performers, in contrast, performance may be described as ‘interactive' on many levels: interacting with acoustic musical interfaces (their instruments), communicating with composers and audiences, mediating the data of a score, negotiating prosthetic devices (microphones, loudspeakers, pedals, sensors), and interacting with invisible chamber music partners (whether backing tracks or responsive computer programs). There has been little public discussion about these issues. This paper will therefore discuss various elements of interactivity in electroacoustic music from the performer's perspective, with the goal of promoting and facilitating satisfying collaborations for both composers and performers. Discussions of pieces for flute and electronics will demonstrate various issues in performing with electronics; describe ways in which works and systems have been designed to work effectively as chamber music; and offer insights into the process of collaboration between composers, technologists and performers.