Technology influences all art, and therefore all music, including composition, performance and listening. It always has, and it always will. The multiple relationships between technology and composer and performer are dynamic and of paramount importance to each party. And a true consideration of any aspect of music requires that all three areas be examined. This has always been a part of music, and so these relationships are inherently important within computer music. The difference is that electronic technology has caused a fundamental change for all aspects of music, a difference that is as pivotal in the history of Western music as was the shift from oral to written preservation of music over a thousand years ago, and then also the accessibility provided by printed music five hundred years ago. In computer music, all parties are always acutely aware of the presence and influence of machine technology in both the visual and audible realms.