After a two year court battle in California, the legal challenge to copyright in one of the most famous songs in the world – Happy Birthday To You – has come to an end.

The case was brought by a group of filmmakers seeking to challenge Warner/Chappell’s purported ownership of copyright in the song and also repayment of licence fees they alleged had been wrongly paid to Warner/Chappell for use of the song. But according to recently filed US court documents, the parties have agreed to settle the long running dispute.

Songs are protected by two separate copyrights: copyright in the lyrics as a literary work and copyright in the underlying music as a musical work. In the claim against Warner/Chappell, it was common ground that copyright in the tune expired long ago – the dispute focussed solely on copyright in the lyrics. Under UK (and EU) law, copyright in song lyrics lasts until 70 years after the death of the author so although the song was written over a hundred years ago, the right is still very much alive.

The terms of settlement have not (yet) been made public, but the case progressed far enough for the judge to issue a decision that Warner/Chappell do not own a valid copyright in the Happy Birthday lyrics. That decision at least seems likely to end Warner/Chappell’s royalty stream from licensing the song for use in films and television, whatever the terms of settlement.

The history of the song dates back over 120 years. In around 1893, two sisters named Mildred and Patty Hill authored a song called Good Morning To All. The lyrics to Happy Birthday are set to the melody from Good Morning – whose lyrics are similar – however, the origins of the Happy Birthday lyrics are not clear. While there was evidence that the Hill sisters had assigned copyright in Good Morning, there was no clear evidence that they had authored the lyrics to Happy Birthday and, if they had, that they had assigned copyright in those lyrics to Warner/Chappell’s predecessor in title. The latter was fatal to Warner/Chappell’s claim to copyright. Warner/Chappell had the burden of proving the necessary chain of title to copyright in the lyrics and, according to the US decision, they failed on this technical, yet crucial, hurdle.

According to US court documents, Warner/Chappell had been making an estimated US$2m annually off the back of licence fees for use of the song in film and television, relying on its purported ownership of copyright in the lyrics.

With this level of revenue at stake, and given the limited scope of the judge’s decision – he made no findings of fact in relation to who authored the lyrics – it was not surprising that someone else emerged from the woodwork with a claim to copyright in the lyrics in place of Warner/Chappell – in this case, a US charity with links to the Hill sisters. However, with the case settled, that claim will not be resolved any time soon.

With copyright in the lyrics not due to expire in the USA until around 2030, there continues to be risk in making unlicensed use of the song. Reciprocal arrangements for the protection of copyright internationally likely protect the lyrics in Europe, but only until the end of 2016.

The case highlights the difficulty in evidencing rights in copyright works created so many years ago and the importance of establishing an unbroken chain of title – something that becomes more difficult as the years pass, even more so when you are looking back from the outer limits of copyright protection, some 70 years after the death of the author.