Roomtone Variations by Nicolas Collins/p>
"In Roomtone the resonant frequencies of the concert hall are mapped by computer, in real time, through acoustic feedback, and projected as staff notation (this takes a little less than 2 minutes). The strongest, most resonant pitches appear first, at the left, the weakest at the far right. Once the staves are filled the musicians improvise variations on these notes (and some octaves) as they are highlighted, gradually stepping through a site-specific architectural tone row. This video is of the first North American performance, by Fred Frith's Improvisation ensemble at Mills College, Oct. 5, 2013." (text from YouTube description)
Thanks to Nick Didkovsky for pointing this one out!