As a long time member of the Folk Song Society of Greater Boston, I don't recall this ever being a problem. Pete Seeger did a concert for us and recorded it as an example of how people should sing along.When I moved to New Hampshire I was amazed to find that artists like Bill Staines, John Mccutcheon and Tom Paxton had to beg the audience to sing. At Old Songs this year, some poor, tone deaf woman told me I had a beautiful voice. Either she or I had had too many beers. I would never knowingly sing loud enough to bother anybody.