Phedra by Tangerine Dream
Brilliant. Saw them in concert once (performing Phaedra). Unusual but brilliant.
In the days when smoking in concert halls was allowed yet the cigarette companies were not "suppliers" that evening.
Couple of Moog banks set up on stage under dull grey'y blue lights. Performers walked on, sat down and player for an hour, got up and walked off, no clapping at any point. 15 mins later they walked back on, played for another hour, got up and walked off, no clapping at any point. End of concert. Stage lights didn't change atall.
And even the non-smokers were not needing alcohol ...
Probably one of my all time best concerts.