Dress up party: go out all decked out

I'm going to the opera tonight -- not everyone's cup of tea, I'll admit. But a "fancy night out" might just be a girl's dream come true. How about a party for a few good friends who dress up in their best finery and attend a matinee opera (try something light like a Mozart comedy or an operetta), musical theater, the ballet, a play, or the symphony. For younger kids who might not master a full performance (or who's parents can't justify the full ticket prices), some companies will allow small groups to attend a dress rehearsal for no or little charge. 

Follow (or begin) the party with a tea party, at home or at a fancy little sandwich and cookie place. I've heard The Beehive Tea Room in Salt Lake City is good. Anybody been there?