Performances [of music,ed.] can occur in different times and different places with different performers and still be authentic instances of that performance. In the performance of a musical work it is recognised that there is a gap between a work as represented as a score and its performance. This allows us to speak of good and bad performances while still being able to say a work is still the same work even if badly performed. There is room for interpretation. [...] While it is true that time-based media works and performances share the property of duration, which marks them out from traditional static arts such as painting and sculpture, this is not the property that most strongly distinguishes these works as being akin to performance. Nor is it the magical transformation of electrical waveforms of encoded media into sound and picture. Instead it is in the fact that the work has to be completed in the gallery in a second stage of creation that is the crucial feature from the analogy rather than the fact of playback. An element of indeterminacy is not present in the playback of media but is present in the act of installing an installation. Laurenson, Lecture 2006