Matthias Gommel's Delayed places two participants in conversation via headsets–except their communications are postponed for five seconds.
No instructions are given when you encounter this work; it's a game of trials and tests and repeats. It's striking that this piece originates from 2002, precisely when it would have registered most strongly around the can-you-hear-me-now ubiquity of mobile phones and their attendant stuttering rhythms.
In one way, it's a work located in that exact year. But in the museum context, like this show at SFMOMA from 2009, it becomes an additional performance as well.
More on Gommel's web site.
[In both images, two people stand opposite one another wearing headphones that hang from the ceiling, speaking and gesturing to one another. Copyright M. Gommel.]