Define "public". A summer camp campfire is considered public and everything from Happy Birthday onward has been litigated for royalties when sung there.
And the author will not see the royalties. The collection agency will collect them by pressuring establishments to pay a seasonal protection fee, but it offers them blanket protection and does not require a logging of the actual songs, writers, or publishers involved.
So if you pay BMI or ASCAP, your bar is protected if any musician covers their material or if someone plays a CD of their protected songs. But none of that money BMI or ASCAP collected will go to the artist because they do not have a record of who to pay it to.
There's probably a more precise legal definition, but pretty much anything big enough to get noticed. An impromptu bonfire on the beach is unlikely to attract any attention. But a summer camp, where parents pay to send their kids -- and campfire sing-alongs are part of the experience they're paying for -- is a whole 'nother thing.
The Boy and Girl scouts have dodged this by putting together official songbooks of original and public-domain material, and some summer camps do the same -- my sister always used to come home from camp having learned a lot of new songs unfamiliar to anyone who didn't go to that camp.
And the author will not see the royalties. The collection agency will collect them by pressuring establishments to pay a seasonal protection fee, but it offers them blanket protection and does not require a logging of the actual songs, writers, or publishers involved.
So if you pay BMI or ASCAP, your bar is protected if any musician covers their material or if someone plays a CD of their protected songs. But none of that money BMI or ASCAP collected will go to the artist because they do not have a record of who to pay it to.
ASCAP conducts surveys to see who's getting played, and allocates royalties accordingly in cases (like most bar bands) when no set list is provided. I assume BMI does the same. The money doesn't just disappear into a slush fund.