I had a dream last night. I was in a supermarket, conducting an orchestra. I don't know how the musicians could see what I was doing, since they were distributed around the various aisles: woodwind down by the baked beans and dogfood, violins and violas bathed in the cold light of the freezer cabinets, brass at the back of the hall, with the alchohol and crisps. A solo cellist sat by the checkouts. In the dream, the music gradually subsided, leaving only the solo cellist whose melodic line rose and fell to the movement of my hands.
Something like it would, I decided, make a wonderful piece in real life. The listeners could come and go as they pleased: there would always be a cacophonous wash of sound in the background but they would hear the music played by the musicians closest to them in some detail. At any one time, some musicians would be closer than they usually are in a concert hall, others further away, mostly invisible. Various soloists could wander around. There could be multiple conductors.
As for the form and style of the music, in my dream the music was discordant and varied between the frenetic and the static. There was no sense of musicians playing together in strict time. Thinking about it today I decided the music could ebb and flow like a tide: what would begin as discreet sounds surrounded by silence would build into a rich, chaotic climax, only to subside, then build again, and so on. It could go on all day. In fact, if the musicians operated a discreet shift-system it could go on indefinitely.
No doubt such a piece could be composed and organised. This would involve a huge effort. However, I offer it here as a "thought piece", as imagining it requires virtually no effort at all!