Brian had 8 or so 4-6" telescopes in the outdoor arena. Each had a light intensity to voltage convertor fitted, the idea being that a stars twinkle would produce a low frequency signal that could be fed into an analogue synthesiser (like my old Pro-One) to module a sound by frequency or amplitude. During the performance each telescope could be steered onto a different star in turn, or onto the moon, or the performers could manually obstruct the light to cause a variation.
Great in theory, but of course this being an English sumer there were few stars to be seen, and the moon was birght when up, but regularly obscured.
The start was delayed and delayed hoping for better weather, but in the end Brian wisely just went for it, and everybody was rooting for him. In the end I think the performance had next to no stellar input, lots of manually "twinkle", but Brian produced some really good white noise sculpted sounds that had everybody enthralled. The moon and the sky added to the atmosphere, if not the sounds. All in all a success, and well worth trying again.