Here are two versions from You Tube. If played simultaneously they produce a curious phasing synchronization - a mad mad improvisation.
INSTRUCTIONS: Start the top video first. When it gets to 5 or 6 seconds start the second. You might need to let both videos load completely first. The vagaries of Internet speed may affect your personal experience.
Watch the players faces for best effect.
If you have trouble with this, you might try this link instead where the two will start automatically. Good luck.
The separate videos are here and here.
Thanks to Tom Brodhead for sending me the link to performer two. He compared the experience of listening simultaneously with the nausea of radiation therapy.
Shard Tags: Shard. . . Elliott Carter. . . solo guitar