(Re-) Presenting an altered interactive system. On et ego, a piece for classical guitar, two piezoelectric microphones and electronics

INTRODUCTION: Starting from et ego, a piece for classical guitar and electronics, this paper aims to introduce the notionof the interactive system as a tool to understand the musical activity developed by a composer and/or performer inrelationship with an instrument and a score.OBJECTIVES: The primary objective is to show how the equilibrium within this interactive system can be affected by theintroduction of an external technology.METHODS: In et ego, the external technology is represented by two piezoelectric contact microphones placed on thesoundboard of the guitar, which creates an interference within the usual performer/instrument relationship. The performerhas to interact with these microphones and with a differently amplified classical guitar: the piezoelectric microphones makevery tiny sounds audible and emphasize percussive sounds while feeding the patch for the live electronics. Consequently,the composer enacts different strategies to understand and represent this enriched vocabulary.RESULTS: The use of piezoelectric microphones allows for working with specific gestures and extremely delicate sounds,enriching the vocabulary of sound material available within the compositional process. The use of notation becomes part ofthis process of comprehension and translation of different aural images.CONCLUSION: The interdependencies between the agents of the system, constantly challenged by different levels ofinterferences, reveal the perceptual and recursive nature of the compositional labour.