More info from the Mustang page (it's not in the album/song database, but in the concert chronology)
Date: Monday, October 9th, 2000
City: Ystad, Sweden
Venue: Ystads Konstmuseum -- Kulturbro 2000 Festival
Notes:
- This was Mats Gustafsson's night. It consisted of a performance of his piece "Hidros 3", which lasted 70 minutes.
- Mats played saxophone, Kim Gordon provided vocals (lyrics apparently written by Patti Smith), Lindha Svantesson provided vocals as well, and Jim O'Rourke did a live mix. These 4 were in the large chamber of the museum.
- Thurston Moore, Lee Ranaldo, Steve Shelley, Loren Mazzacane Connors, David Stackenäs all played guitar in their own separate rooms. Each room was missing a wall, so you could observe the performers (they were, however, blocked off with a rope and a sign that read "Do not touch the musicians").
- Apparently Lotta Melin was involved as well, though I'm not sure how.
http://www.sonicyouth.com/mustang/cc/100900.html