Oh, I just started it up again and... I'm sad I missed out on a bunch of the dances too. :'( I think there needs to be clearer indication that you only have two chances at the dance. Since I only had a few minutes to play, I did one dance at a time figuring I could go back and revisit, but now I really do have to start over completely from scratch. I don't suppose you have a save file that's at the ending with all the ghosts unlocked, right before the dance?
Sorry to be a bother. I loved all the ghosts and want to see the rest of their stories!