Days before trial and over two years of federal court litigation, a confidential settlement has been reached that would allow the lyrics to the “Happy Birthday” song, one of the world’s most popular songs, to enter the public domain.

The origins of “Happy Birthday” date back to 1893 with the publication of “Good Morning to All,” written by Mildred Hill and her sister Patty, a kindergarten teacher in Kentucky, which had the same tune but different lyrics.Years later, the lyrics to “Happy Birthday” were adapted to the song’s melody. The “Happy Birthday” song was then published in a number of sing-along collections and music books. In 1935, the publisher of one of those books filed for a copyright for the lyrics and music. In 1988, the copyright was transferred to Warner Music.

The lawsuit was brought by a filmmaker who was working on a film about the origins of the song who had to pay Warner Music $1,500 to use the song in the movie. The filmmaker argued that the “Happy Birthday” song, which generates an estimated $2 million a year in royalties, should be in the public domain so that no royalties should be owed for use of the song.   In September, 2015, a federal judge ruled that Warner Music did not have a valid copyright claim because the original publisher only had rights to a specific arrangement of music in the song and did not have a claim to the lyrics.