It's a song known around the world; "Happy Birthday to You" is performed, heard, and played millions of times every day, but it's also a major moneymaker for Warner Music subsidiary Warner/Chappell, which owns the copyright to the song. Jennifer Nelson, a filmmaker who was producing a documentary on the song, discovered that to use the track in a single scene would cost $1,500. Although she agreed to the fee and signed a licensing deal, she's now filed a lawsuit in the hope that a New York court will invalidate Warner Music's copyright claim.

Nelson says that the song, which is an adaption of the 19th Century song "Good Morning to All," is in the public domain. A full copy of the filing, available at Techdirt, makes for entertaining reading. The lawsuit says that "irrefutable documentary evidence" dating back as far as 1893 shows that the copyright to any part of the song expired no later than 1921. It adds that if Warner Music "owns any rights to Happy Birthday to You, those rights are limited to the extremely narrow right to reproduce and distribute specific piano arrangements for the song published in 1935." The filing calls for the song to be made public domain, and asks the Warns Music pays back the millions of dollars it's collected through "unlawful licensing fees."