US federal judge, George King, ruled that the original copyright was only granted for specific arrangements of the music, not the song itself.
The original copyright was filed in 1935 under the name Good Morning To All by Mildred and Patty Hill. Warner/Chappell acquired the copyright in 1988; however, the Judge said, “The Hill sisters gave Summy Co the rights to the melody, and the rights to piano arrangements based on the melody, but never any rights to the lyrics.”
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