Typically, this involves a performer playing an instrument while a computer creates music that is, in some way, shaped by the performance. Interactive music techniques developed over the past few years can apply to multimedia interactivity in the arts, in CD-ROM titles, installations and performance works. Continuous control over musical parameters adds a level of variation and interaction not usually seen in commercially available titles. Techniques for analyzing performance action may also be applied to trigger or modify visual elements, such as text or video, in a concert presentation using computer projectors and large monitor systems.
Performers listen to each other while they play, reacting all of the time to what they hear.
Musical performances usually stay within a consistent context that creates a feeling of understanding among the musicians and the audience without being entirely predictable. Interactive music is a natural extension of a long history of collaborations. Interactive music uses software to interpret human action to effect some aspect of music generated or modified by computers. Performer's actions directly or indirectly alter parameters that control computer music processes. Performance information may be used immediately to alter compositional algorithms, or may be viewed over longer spans of time, such as analyzing phrases or sections of a work.