Thank you all for your comments. I really appreciate them.
A few notes:
Anyone who thinks the Deliverance theme (with its overtones of ignorance, and, well, forcible sodomy) is bluegrass has probably never heard any bluegrass music.
Industrial metal - well, how is it possible to ride a train (on the shores of Lake Erie, for example) and hang around waiting for a train, without being exposed to the sights of metallic industry, and industrial metallic noise. By comparison, the music we play is mostly received as quite soothing.
It does make a great deal of sense to be considerate of others, of course. Which we will do. Specifically, if anyone within hearing and/or visual range expresses displeasure with our music, you may be sure we'll stop. One does not play casual music in public for a few decades without learning this.
Anyone who rides the train for complete privacy, that is, no exposure to the personalities of others, would be far better off riding the airplane, where no one talks to one another, nor looks others in the eye. One of the most frequent comments I hear about riding trains is, how nice it is to meet folks. And putting up with people's loud cell-phone conversations pretty much constantly seems to go with the turf too. I can live with it, and if not, I'll politely ask them to tone it down or stop. I welcome the same communication regarding the music.
Best,
David