The melody of "Happy Birthday to You" comes from the song "Good Morning To All", which was written by American sisters Patty Hill and Mildred J. Hill in 1893 when they were kindergarten school teachers in Louisville, Kentucky, at what is now the Little Loomhouse. The sisters created "Good Morning To All" as a song that would be easy to sing by young children. The combination of melody and lyrics in "Happy Birthday to You" appeared in print beginning in 1912, and probably existed even earlier. None of these early appearances included credits or copyright notices. The Summy Company registered for copyright in 1935, crediting as authors Preston Ware Orem and Mrs. R.R. Forman. In 1990, Warner Chappell purchased the company owning the copyright for US$15 million, with the value of "Happy Birthday" estimated at US$5 million. Based on the 1935 copyright registration, Warner claims that US copyright won't expire until 2030, and that unauthorized public performances of the song are technically illegal unless royalties are paid to it.