A federal court in New York ruled, that the daughters of a writer whose nursery-rhyme appeared in the TV sitcom “The Big Bang Theory” won’t be able to bring copyright infringement claims against the show over its use of the ditty “Warm Kitty”. The court held that Ellen Newlin Chase and Margaret Chase Perry can’t prove their late mother held the copyright to the song, which TV character Sheldon taught a friend to sing when he was ill in an episode of the sitcom.

In December 2015 Chase and Perry brought an action against Warner Bros. Entertainment Inc., CBS Corp., Fox Television Stations Inc. and other associated companies, alleging “the show used their mother’s work without proper permission”. Edith Newlin, a nursery school teacher and writer, had penned “Warm Kitty” for a 1930 s song book that was covered by a blanket copyright notice, according to the opinion. The defendants used the lyrics in a little modified form, including on the television show ‘The Big Bang Theory’, the opinion said.

The court held it is governed by the Copyright Act of 1909, because of of the song’s publication date. And under the Copyright Act of 1909, authors were granted an initial 28-year copyright term, and if the owner dis not renew the term, the work become public domain. There is not any evidence that Newlin did renewed the owner term. After the 28-year copyright term the work went in into the public domain. Still, the opinion said, the owner of the songbook, “Songs for the nursery School”, had renewed the copyright for the book in 1964.However, Copyright Law “granted the owner the right to renew composite elements and the individual author the right to renew his contributions,” said the opinion. Meaning the holder of a collective work could only renew the rights to the contributed parts he or she had collected from the individual contributors, said the court. And the court found that Chase and Perry couldn’t prove that Newlin had assigned the song rights to the book owner and that it was covered by the copyright renewal. Furthermore they could not prove they had a valid claim to the work, according to the opinion. The court shot down the arguments that Newlin had assigned the songbook a “common law copyright” while retaining a personal “copyright” and “other rights”