Music performance and the mediality of the musical instrument: an Activity Theory perspective

Music performance is all about the expressive communication of artistic ideas. To express these ideas to an audience, musicians depend on their musical instrument. Within the embodied music cognition paradigm the musical instrument is considered to be a multimodal technology that mediates between the performers mind (musical ideas) and physical energy (the sounding music) (Leman, 2007). But what exactly does this mediating role consists of? Is the musical instrument a mere material channel through which pre-defined meaning is transferred to the listener? Or does it play a constitutive role for the generation and communication of musical meaning?