Yesterday I went to a BEMF fringe concert by Rook. Unlike The Peabody Consort, whom I also saw, they were not dressed in black. They all had on jeans, but three of the guys had untucked dress shirts over them, while trombonist Paul Von Hoff was wearing a suit jacket and tie over his (tucked in) dress shirt. Maybe that is based on their individual comfort level more than anything else. Here is a video (as a trio, missing violinist Jakob Hansen) in which Von Hoff is slightly more casual (no tie), Jeremy David Ward is wearing (I think) exactly the same clothes he had on yesterday, and harpsichordist Mark Shuldiner is wearing shorts and a t-shirt. https://www.youtube.com/watch?v=nBLHbIgP3X0
Most of us in the audience were dressed for comfort as well. In my case, I was (unusually for me) wearing sweat pants, having thought to move stuff around in the basement before I blew it off to hear live music instead. I'm dressed that way again today, and am again considering skipping it in order to hear a mid-day concert. I will tidy something really soon, I promise.