I haven't seen
Eyes Wide Shut, so I'll comment on the original question posed by Duchess.
I've never been to an opera myself. I've always been curious about seeing Wagner's
Ring cycle though, and the Lyric Opera's doing the cycle next year for their 50th anniversary, so ummm....
Duchess, I don't think you'd miss with either choice, but I'd probably pick
The Magic Flute myself.
Mozart is "easy listening". I like his music for having the qualities of being "thinking music", music to listen to while concentrating on a problem. Not as intense as Beethoven for the most part, though there's some intense music there, yet for the most part his music has the quality of being "graceful". BTW, his thread has inspired me to play one of his "intense" pieces, his 40th Symphony.
Foul, I remember reading a story about Bach traveling to try to meet Handel. Handel was regarded, in their lifetimes, as the greatest living composer, and a writer of operas. Anyway, Bach walked to where ever it was that Handel was living at the time, only to find out that Handel had moved that morning. The writer mourned that they could have learned from each other. Handel learning Bach's compositional theory, and Bach about composing operas.