I just bought a video of films produced by artists related to the Fluxus group in the mid-late '60s - and one of the films is by our man Cale. It's silent, and consists of a totally black screen with two flashing lights that may or may not be from police cars. Only 90 seconds long, kind of like a visualisation of a La Monte Young minimalist drone, apparently shot in London.
Anyone know any more about it? I don't think it's mentioned in Welsh For Zen, and I wasn't aware of any links with the Fluxus group... (I guess it would be through Jonas Mekas?)