The Guinness Book of World Records said that “Happy Birthday to You” is the most recognized English-language song. There’s no reason at all to doubt that claim. While “Somewhere Over the Rainbow” may be more beloved, there are fewer occasions to sing that song, and it’s a lot harder to sing it well.

In other words, the song “Happy Birthday to You” is part of everyday life. It would be surprising if friends and families celebrating a birthday didn’t sing it. It’s like the National Anthem before a ballgame, like saying “I love you”on Valentine’s Day, and like saying “good morning” in the morning.

If copyrighted songs could become generic in the way that trademarks that become synonymous with the goods whose source they identify, then, “Happy Birthday to You” would be declared as being in the public domain because the song is inherently part of American birthdays, seemingly belonging to everyone and no one in particular at the same time.

Some people may find it impossible to believe, but, as of now in the records of the Copyright Office and the public performing rights organization ASCAP, the copyright of “Happy Birthday to You” is alive, well, and proprietary to the major music publisher Warner/Chappell.

Why write about the song now? Documentarian Jennifer Nelson’s company, Good Morning to You Productions Corp., filed a lawsuit seeking certification of a “class” of companies and people who have paid for use of the song. The plaintiff is asking for a declaration that the song is in the public domain. Further, among other things, Good Morning to You Productions wants the court to order compensation to those who paid licensing fees for use of the song, when under the plaintiff’s theory the song wasn’t copyrighted.

Good Morning to You Productions paid a $1500 licensing fee to Warner/Chappell to include the song in a documentary film about the history of the song. Rather than claim the use was a “fair use”, the plaintiff asserts that the song is in the public domain because the song is so old that any copyright protection has expired. Further, the plaintiff essentially asserts that the copyright history of “Happy Birthday to You”’ is so uncertain that no own owns it.

The complaint filed in federal court last month provides a detailed history of the development of the song. The plaintiff states that the song, or at least parts of it, go back to 1893 when the children’s song “Good Morning to All” was published. “Good Morning to All” was written by two sisters, Mildred Hill and Patty Smith Hill, containing the familiar melody we know as “Happy Birthday to You.”

The plaintiff’s lawyers allege that Warner/Chappell collected about $2,000,000 a year from public performance and other licensing of the song. So, owning this song is like receiving a birthday present pretty much every day of the year.

What’s significant about the case? First, an important part of popular culture would be declared free for use by anyone if the plaintiff succeeds. Second, the case might provide insights on chain-of-title in copyright cases. Attacking copyright ownership of old works seems to be increasingly frequent. Third, if the highly unusual copyright litigation class action sought is certified by the district court the case might impact other situations that involve a long and complicated copyright history and provenance.

Someone will play a song about a happy copyright day in court. We just don’t know whose name will fill in the blank space after “Dear” will be heard.