The most famous and most frequently sung song in the world is probably the “Happy Birthday to You” song. The melody of “Happy Birthday to You” was created in 1893 by a pair of teachers and sisters from the United States. It is used for greetings in the classroom. The title of the song is “I wish you good morning.”
Later, I don’t know who filled in the lyrics that wish you a happy birthday. The earliest birthday music was registered by the American Sami Company in 1935, so for a long time on a legal level, it was performed in public. This song is illegal.
Fortunately, the copyright of “Happy Birthday to You” was taken back in 2015, and the song officially became a public product.