Disclaimer: I love the opera scene and its music.

However, in the context of the game's story, the entire opera scene makes virtually no sense.

So, the actress playing Maria is replaced by Celes. Fair enough. After all, we're told that Setzer's going to arrive in his airship and whisk 'Maria' away for romance. But this raises some important questions:

(1) If the Impresario knows about Setzer's plan, he should just tell Maria not to go along with it. She's his employee, after all, and should be contractually obliged to avoid ruining an expensive show.

(2) If Maria's not actually involved in Setzer's plans, then that means he's basically a globe-trotting abductor and probable rapist - someone who deserves to be stopped, preferably with deadly force.

So either Maria is a pathetic failure of an opera star, unable to curb her hormones for a couple of hours until the show's over, or Setzer is a disgrace to humanity.

Then there's the issue of the substitution. The Impresario wants Celes to sub for Maria so that the star of his show won't elope or be abducted in the middle of a performance. However, even with Celes on stage instead of Maria, Setzer is going to go ahead with his diabolical plan - he doesn't know about the switch, so he's still going to crash the opera and try to take off with the star.

From the Impresario's point of view, the night is still ruined either way. The only upside is that Maria may remain to perform again another day. Unless, of course, she wanted to flee with Setzer all along, because there's nothing to stop her leaving with him later.

Finally, there's the most obvious flaw: Celes is 18 years old, a genetically-enhanced super-solider who's achieved the rank of General while still in her teens. She's a gifted soldier and military leader. So when the hell did she also become a musical genius, who can read the libretto once and then flawlessly perform the lead role in an opera from memory? I seriously doubt that scales and arpeggios were at the core of the Empire's military curriculum.

Now, it's been years since I played this game, so I might be remembering some of these details wrongly. But from what I recall, the opera scene's really hard to justify or fully explain in any reasonable, internally consistent way.