Okay, yes, this has been posted many times, but not in this best quality it deserves. Broadcasted at Hamburg, West Germany, 11 March 1972, and of course, Helen Reddy's cape strikes again! Introduced by Ilja Richter.
Albeit this episode of "Disco" was filmed in videotape, this is in at least DVDworthy quality comparing to other videos here. Some are a bit out of sync, so I tried my best to get it to a tee.
n.b. The soundtrack of the depicted video is retained for posterity.