Sorry, that skirt length does NOTHING for my legs!

More seriously, in houses like these where a sizable number or the audience are tourists, my feeling is really saying "shorts, tee-shorts and other very informal wear probably aren't appropriate".

Add to that the fact that more and more people buy their tickets online - many people will not see the poster until they arrive the evening of the performance.

I hope that the OP will report back after the performances on what he/she saw, both on the stage and in the audience.