Refrain, Zyklus, Klavierstück IX or X, Mikrophonie I

Concert date: 
Thursday, December 1, 1966
Works performed: 
Klavierstück IX
Klavierstück X
Mikrophonie I
Refrain
Zyklus
Concert venue: 
Fore Hall, Glasgow University
City: 
Glasgow
Programme text: 
Not sure if this is just a playback of Mikrophonie since only performers listed are KH, Kontarsky, and Caskel.