Interactivity refers broadly to human-computer musical
interaction, or human-human musical interaction that is mediated
through a computer, or possibly a series of networked computers
that are also interacting with each other. Often, an interactive
performance, composition or improvisation will involve the
creation or programming of software that will respond to pre-
determined aspects of a live performance. The software will then
determine other aspects of the music, either generating
synthesised sound, or modifying in some way all or some of the
’live’ sound. The behaviour of the computer may be highly
determined or indeterminate as defined by the musicians, and may
be modified from performance to performance. The exact musical
role of the computer may even be modified in real-time during
the course of a performance. Interactive music-making introduces
and often utilises notions of virtual instrument, virtual
performer, virtual composer, and even virtual listener.
Interactive music-making frequently blurs th