Sorry that a couple of people missed the point of the barber shop story. The radio compnay pays to broadcast music as entertainment. The hairdresser was using a radio in his shop as an attraction in his business --- a completely separate matter. Nobody asks you to pay for listening to radio music at home, that's not your business. The radio station, whose business it is, pays. If you run a restaurant or a shop that uses radio music as an attraction, why shouldn't you pay the people who create it?
If you sing for fun in non-commercial venues there's no problem, so sing for fun! That's what it's supposed to be isn't it?