Oh yeah, one thing that I haven't seen, but would love to, is what I think might be the first surround sound works ever. . . by Gesualdo, IIRC, during the Renaissance. Cathedrals are shaped like a cross, and so the distances differed at each end. He wrote works for 4 choirs, each choir at each end, and wrote with the delays in mind when writing.
I've also read the Glenn Gould Reader (collection of all his
published writings), and he talked about wanting to record a 4 voice fugue on 4 mono tracks, then play them on 4 speakers, one on each side, and sit in the middle to listen to them. He never had yet done that according to what he wrote in the book.