3 of a Kind: Mirror Mirror and two prior fractured fairy-tales that end on a song.

Why Relativity saw fit to release this climactic dance number from Mirror Mirror well-ahead of its theatrical release, I cannot say.  But while it's pretty disconnected from the film, it does reveal a pretty big spoiler involving the fate of a major supporting character (and also ruins one of the biggest 'wtf?' cameos in recent memory).  It may not be fair to continuously compare Mirror Mirror to the somewhat similar Ella Enchanted, but it is worth noting that they actually end in pretty much the same way, albeit with an established song as opposed to an original Bollywood-ish tune.