The melody for “Happy Birthday to You” was composed on June 27, 1859, by schoolteacher Mildred Hill. Its original title was “Good Morning to All.” Her sister, Patty Hill Smith, added the birthday lyrics later. “Happy Birthday to You” is probably the most frequently sung song in the world.

“Good Morning to All” was published in 1893 by The Clayton F Summy Company. A later publication with the combination of the melody and lyrics “Happy Birthday to You” was printed in 1912. There was no copyright notification in the early editions. In 1935, Summy registered a copyright crediting authors Preston Ware Orem and Mrs. R. R. Forem.

In 1988, Warner/Chappell acquired The Summy Company for $25 million, with “Happy Birthday to You” valued at $5 million. Warner claimed that the copyright would not expire until 2030, and that public performances of the song were illegal unless royalties were paid. (In February 2010, the royalty for a single use was $700.) “Happy Birthday to You” may be the highest earning single song in history.

In 2013, documentary filmmaker Jennifer Nelson had paid $1500 for rights to the song as part of a documentary she was making about the song and its history. As she developed the story for her documentary, she discovered extensive research by American law professor Robert Brauneis, who had concluded in 2010 that the song was “almost certainly no longer under copyright.” On June 13, 2013, she filed a class action suit against Warner/Chappell seeking the return of her money and all royalties collected from the company from other filmmakers since 2009.

In September 2015, a federal judge ruled that the Warner/Chappell claim was invalid, ruling that the copyright registration applied only to a specific piano arrangement of the song and not to its lyrics and melody. In 2016, Warner/Chappell settled for $14 million.

On June 30, 2016, the final settlement was officially granted, and the court declared that the song was in the public domain. The following week, Nelson’s short form documentary, “Happy Birthday: My Campaign to Liberate the People’s Song” was published online by The Guardian. https://www.youtube.com/watch?v=y3whtVeMalo&t=873s