Most people in California sing ‘Happy Birthday To You” without thinking about copyright infringement. However, the famous song has only recently been added to the public domain. On Sept. 22, a U.S. District Court judge ruled that the copyright for ‘Happy Birthday To You” was not valid, and the copyright owners can no longer collect royalties for the song.

After two sisters composed ‘Happy Birthday To You” in the 1800s, Clayton F. Summy Co. acquired rights to the song and then sold those rights to Warner/Chappell Music Inc. in 1988. In the recent court case, the federal judge found that Summy Co. had never actually obtained the rights to the song lyrics, and no valid copyright of the lyrics ever existed. The judge’s recent decision to release ‘Happy Birthday To You” into the public domain was the result of a lawsuit that was filed by Good Morning to You Corp. two years before.

Warner/Chappell Music Inc. purportedly bought ‘Happy Birthday To You” for $15 million. Since the purchase was made, Warner/Chappell has been collecting royalties from anyone who uses the song in a commercial enterprise such as a television show or movie. Revenue from ‘Happy Birthday To You” reportedly brought in about $2 million per year.

Copyrights for popular songs and song lyrics can be incredibly valuable due to the royalties that may be collected for their use. A person who owns intellectual property like a song may want to talk to a lawyer about whether a valid copyright exists. A lawyer may also be able to help a copyright owner to protect the intellectual property from copyright infringement.