Patty Hill was a kindergarten principal in Louisville, Kentucky, developing teaching methods at the Little Loomhouse;[6] her sister Mildred was a pianist and composer.

[10][11] Warner claimed that the United States copyright would not expire until 2030 and that unauthorized public performances of the song were illegal unless royalties were paid.

The Supreme Court upheld the Act in Eldred v. Ashcroft in 2003, and Associate Justice Stephen Breyer specifically mentioned "Happy Birthday to You" in his dissenting opinion.

[26] The first book including "Happy Birthday" lyrics set to the tune of "Good Morning to All" that bears a date of publication is The Elementary Worker and His Work, from 1911, but earlier references exist to a song called "Happy Birthday to You", including an article from 1901 in the Inland Educator and Indiana School Journal.

[citation needed] The Summy Company, publisher of "Good Morning to All", copyrighted piano arrangements by Preston Ware Orem and a second verse by Mrs. R. R.

[31] Warner/Chappell claimed copyright for every use in film, television, radio, and anywhere open to the public, and for any group where a substantial number of those in attendance were not family or friends of the performer.

Her complaint relied heavily on Brauneis's research, and sought the return of her money and all royalties collected by the company from other filmmakers since 2009.

[35][36][37] In April 2014, Warner's motion to dismiss had been denied without prejudice, and discovery began under an agreed plan with respect to Claim One, declaratory judgment as to whether "Happy Birthday to You" was in the public domain.

[39] Nelson's attorneys Betsy Manifold and Mark Rifkin presented new evidence on July 28, 2015, one day before a scheduled ruling, which they argued was conclusive proof that the song was in the public domain, "thus making it unnecessary for the Court to decide the scope or validity of the disputed copyrights, much less whether Patty Hill abandoned any copyright she may have had to the lyrics".

They had been given access to documents previously held back from them by Warner/Chappell, which included a copy of the 15th edition of The Everyday Song Book published in 1927.

The book contained "Good Morning and Happy Birthday", but the copy was blurry, obscuring a line of text below the title.

The previously obscured line was revealed to be the credit "Special permission through courtesy of The Clayton F Summy Co." Manifold and Rifkin argued that the music and lyrics were published without a valid copyright notice as was required at the time, so "Happy Birthday" was in the public domain.

[40] Warner/Chappell disputed the evidence, arguing that, unless there was "necessary authorization from the copyright owner", the "Happy Birthday" lyrics and sheet music would still be subject to common law copyright as an unpublished work, and that it was unknown whether the "special permission" from the Summy Company covered "Good Morning to All", "Happy Birthday", or both, thus alleging that the publication in The Everyday Song Book was unauthorized.

[19] However, Warner/Chappell had failed to prove that it actually had ever held a copyright to the lyrics, so the court was able to grant summary judgment to the plaintiffs, thus resolving the case.

[47] Before the lawsuit, Warner/Chappell had been earning $2 million a year licensing the song for commercial use,[45] with a notable example the $5,000 paid by the filmmakers of the 1994 documentary Hoop Dreams[48] in order to safely distribute the film.

[18] The following week, Nelson's short-form documentary Happy Birthday: My Campaign to Liberate the People's Song was published online by The Guardian.

[57] In the 1987 documentary Eyes on the Prize about the U.S. civil rights movement, there was a birthday party scene in which Dr. Martin Luther King Jr.'s discouragement began to lift.

After its initial release, the film was unavailable for sale or broadcast for many years because of the cost of clearing many copyrights, of which "Happy Birthday to You" was one.

[59] In 2010, the Western classical music conductor Zubin Mehta conducted the orchestra to play variations of "Happy Birthday" in the styles of various Western classical music composers, including Wagner, Bach, Mozart and Beethoven, and in the Viennese, New Orleans and Hungarian composition styles.