Its now official, Happy Birthday is in the public domain. In a 43-page decision, US District Judge George King ruled that the original copyright on the song, filed by the Clayton F. Summy Co. in 1935, only covered specific piano arrangements, and not the song’s lyrics.
Warner/Chappell, a subsidiary of Warner Music, acquired the copyright in 1988, when it acquired a company that had obtained Summy’s catalog. Warner/Chappell had reportedly earned about $2 million a year in licensing fees for the song’s use in TV and movies.
This decision now means that anyone can use the song for commercial purposes.