I was sitting there, listening to the sound test of Sonic 3 (& Knuckles) in sequence. The songs play in order chronologically (the order the zones appear in the game, starting with Angel Island 1), something I knew.
But why is it that the zone Flying Battery got misplaced back as zone 5 (rather than the ingame order's designation as zone 8)? Could be a glitch, but I think this may mean (40% sure) that Flying Battery may have been a former Sonic 3 zone that got switched to Sonic and Knuckles. Here is the total order the sound test puts the zones:
Angel Island 1 + 2
Hydrocity 1 + 2
Marble Garden 1 + 2
Carnival Night 1 + 2
Flying Battery 1 + 2
Ice Cap 1 + 2
Launch Base 1 + 2
Mushroom Hill 1 + 2
Sandopolis 1 + 2
Lava Reef 1 + 2 ("2" also being Hidden Palace)
Sky Sanctuary
Death Egg 1 + 2
Mini-Boss
Robotnik
Doomsday
Any explanation for FB's misplacement?