How many times have you sung “Happy Birthday” to someone without knowing it was copyrighted? Perform it publicly, and you have to pay a fee to the copyright owner Warner/Chappell Music.

Of course, people sing the song at birthday parties without paying a royalty. But if you want to, say, put the song in a movie? You have to pony up. 

“Warner/Chappell charges sometimes $100,000 or more for a major motion picture use of the song,” says Mark Rifkin, an attorney representing a filmmaker who’s suing Warner/Chappell Music, claiming the copyright is invalid. 

Was Rifkin surprised that “Happy Birthday” was copyrighted?

“I sure was,” he says. “Like most other people I assumed it was in the public domain.”

Filmmakers go to great lengths to avoid the birthday song. Restaurant employees can’t sing it either; they’ve come up with alternatives. If you’ve ever been to a T.G.I. Friday’s, you know what I mean. But these unique birthday songs keep restaurants and filmmakers out of trouble.

Dan Cryan, senior director of media and content at the consulting group, HIS, says you can’t blame people for avoiding the birthday song.

“Performing it in a public space, in theory should incur a fee,” he says.

Warner/Chappell turned down a request for an interview. But Judith Dornstein, an entertainment attorney who represents artists and production companies, says whatever you think of the “Happy Birthday” case, copyrights are an important protection for the entertainment business.

“This is somebody’s work that it took time and effort to put into,” she explains. “This is their living.”

Dornstein says the “Happy Birthday” case is unique. And probably won’t set a precedent. But, until it’s settled, you better be careful about singing it in public.