This is a bizarre story. According to The New York Times, the song “Happy Birthday to You” is not in the public domain:
The dispute stems from a lawsuit filed on Thursday by a filmmaker in New York who is seeking to have the court declare the popular ditty to be in the public domain, and to block a music company from claiming it owns the copyright to the song and charging licensing fees for its use.
The filmmaker, Jennifer Nelson, was producing a documentary movie, tentatively titled “Happy Birthday,” about the song, the lawsuit said. In one proposed scene, the song was to be performed.
But to use it in the film, she was told she would have to pay $1,500 and enter into a licensing agreement with Warner/Chappell, the publishing arm of the Warner Music Group. Ms. Nelson’s company, Good Morning to You Productions, paid the fee and entered into the agreement, the suit says.
This is an interesting piece of trivia:
The lawsuit notes that in the late 1800s, two sisters, Mildred J. Hill and Patty Smith Hill, wrote a song with the same melody called “Good Morning to All.” The suit tracks that song’s evolution into the familiar birthday song, and its ownership over more than a century.
Personally, I sure hope Jennifer Nelson wins this case.