I agree that everyone should be a union member if a union covers your main source or a major source of your income. If, however, your interest in performing is as an amateur (in the sense of one who does it for the joy it gives) it does not necessarily make sense to pay for the pleasure of lifting your voice.I also found it disturbing that people who were playing on the sidewalk were treated like vagrants and, essentially, threatened with the choice of running along or being run in. We are not talking of major performances here.
ps, although I now work as a capitalist, I continue my union activities as an "active retired" member both locally and on the statewide level. My former bosses have real problems with this as they now have no control at all over my activities except to have me barred from the facility, which they cannot do because that would be anti-union activity and actionable.