My memory of Future World is as follows: You'd hear the 1982 Entrance loop all through the entrance area, up the hills on either side of SSE, and through Communicore Central. It would start to fade out as you were leaving Communicore and heading to World Showcase. No music in the Communicore breezeways. No music in the common areas just past the breezeways, but as you'd start walking towards each pavilion its distinct BGM would sneak up on you pretty quickly. In many ways it's not too different than how it is today. I do remember that the south side of Communicore Central was quieter than it is now - once Splashtacular premiered, the BGM was piped through its dedicated sound system and it made the area around the stage and fountain in general much louder than it once was.