>> I really cannot think of anything lessrelevant to a live performance than the way anyone is dressed. (Unless it's central to the show, I suppose)
Then you must never have worked with an orchestra or played a live gig in a band or ensemble.
I did an orchestral session some years ago and requested the players dress formal. Normal attire in the studio is business casual, but it was an evening session and I had clients present. I thought it would be fun. Afterwards, my concert master complimented me on the strategy saying how well the orchestra performed and how attentive and engaged the players were for the recording. Dress is irrelevant?