The Cardew Choir version of
Sonic Chains is a composition for an improvising choir, guided by a
conductor who uses a video
projector and a computer running the Sonic Chains conducting software
to convey instructions to the performers.
The projected display is divided into a three by two array of rectangular regions -- a total of six regions. Before the performance, every choir member should be assigned one of the regions to watch for performance instructions. It's probably a good idea to divide things up as evenly as possible. For example, if there are ten performers, four regions should have two singers assigned to them and the other two should have one singer each. Charts identifying each singer's region should be distributed during rehearsal. (The Sonic Chains Resources page has links to appropriate charts.)
Following the projected display is relatively simple. If your region is blank, don't sing. If it's not blank, it will display one of twelve diagrams (see the Sonic Units page) that indicate the sort of sound to make. The Sonic Unit drawings are taken from Anthony Braxton's musical paradigm chart and, I hope, should already be familiar to many performers.