Possibly the most widely-recognized song in the English language, “Happy Birthday to You” didn’t start out as a song of birthday good wishes. The tune of this beloved ditty was penned in 1893 by school teacher sisters Mildred Hill and Patty Hill. The two teachers wanted a sing-song greeting with which to welcome their young charges to school each day.

Together they came up with the simple tune that is universally sung to the words of what is now “Happy Birthday to You.” In its original form, however, the song went like this:

Good Morning to you,
Good Morning to you.
Good morning, dear children,
Good morning to you.

In fact, these words are often still sung to that same tune today in elementary schools around the globe. Because it’s likely every English-speaking child knows it, it makes the perfect tune to just about any simple lyrical poem.

When the words “Happy Birthday to You” were added to the tune remains something of a mystery. What is known about it is that by 1935 the birthday song had become such a part of popular culture that its copyright was purchased by the Summy Company.

The music publishing company still holds the copyright today. Undoubtedly, Summy saw a potential profit-generator in the humble little birthday song. To date, the company has not dispatched song police to nab every innocent and unsuspecting crooner who belts out the beloved tune at a birthday party. It does, however, receive royalties from many sources.

Technically, any public performance of the song requires that royalties are paid to the Summy Company. Every time you hear it performed in a movie or any otherwise for-profit performance, you might also hear change clinking in the pockets of Summy executives. Canadians, on the other hand, can freely sing the jingle without fear of prosecution. This is because in Canada, copyrights only extend to 50 years after the passing of the author. “Happy Birthday” entered the public domain in Canada in 1985.

Many people are surprised to learn that “Happy Birthday to you” is actually owned by a private company. This is to the consternation of many of the song’s devoted fans. After all, the song’s predecessor, “Good Morning to All,” is currently public domain. Sing that same tune to the lyrics it is more commonly known by, and you may risk having to pay Summy.

Ordinary citizens are miffed that, thanks to some changes in copyright law in the 1970s and 1990s, Summy’s rights to the birthday song were extended. Originally destined for public domain in 1991, Summy will continue to profit from it until 2030. Many people feel that the birthday song rightfully belongs to the public, especially since the Hill sisters never profited from the original tune.

Whether they would have wanted to be is another question. The Hill sisters merely set out to write a catchy and easy-to-sing-and-remember song for children. It’s highly unlikely that either of the teachers ever had the notion that their humble number would become what it is today.

Times have changed considerably since 1893. What was once a simple gift to school children has, in the span of just over a century, become a profit-generating monster, much contended by its advocates.