I do not think the arts are a public good in the US because they are not publicly funded. The *vast* majority of an orchestra’s funding in this country comes from people (consumers) in the form of ticket sales and donations—usually around 70-80% in a lot of budgets (TRG will tell us this too)—not other government, corporate, or grant sources.
I believe in serving as many people as possible and different people as I have written about before, and I even say that a $5 ticket is better than free. People still have to pay for transportation, etc. even when free, so another $5 on top of that does not radically change the overall cost to attend for most income brackets. Again I do not think the arts need to be made publicly available to every single person until there is public funding to support that.
All that said, if you have a model that is working for your chamber orchestra, then you keep that good thing going. I hope tons of people are loving what you are doing and coming back again and again, truly.