Feedback usually makes us think of those ear-splitting piercing tones that come across a PA system when it is being tested before a concert. Perhaps this is something that we would rather avoid having to experience, but this is only one aspect of feedback. Essentially, feedback is a situation created by a loop cycle, where output is fed back into the same system from which it first emerged. This could be a sound system, a visual system or even a mixture of the two. The common feature is the dynamic live quality of what is happening and the fact that there is a possibility of an artist being able to intervene in some way to influence the cycle. The arbitrary nature of feedback can be directed so that it partly conforms to a specific artistic intention.