Have you ever wondered why movies and tv shows never actually have people singing the happy birthday song? Or why restaurants always make up their own incredibly stupid version of it to sing while they bring you your free fried ice cream? It's not because any of these people are interested in creating a new version of the song. Instead, like almost all explanations for the life's oddities, it comes down to a corporation well over-stepping its legal rights to quash the rights of the rest of us.
The funny thing about this is that no one really knows who wrote "Happy Birthday To You," or even when it was written. But this hasn't stopped Warner music from claiming they have the copyright to the tune, though they can't demonstrate how they got it or why it's theirs. But fortunately for them, if anyone wants to stop them from claiming copyright on one of the most-used songs in the world, they need to have the time and resources to challenge a major corporation in court. Not a lot of people have that.
But fortunately for shitty chain restaurants everywhere, someone is finally trying to get Happy Birthday's day in court. Good Morning to You Productions (named for what many believe is the original tune happy b-day is based on) is suing Warner, arguing that even if they ever had a reasonable claim to the copyright (which is questionable enough in and of itself), it would have expired in 1921 at the latest. Good Morning to You is not only suing to end Warner's copyright claim, but to force them to pay back the millions upon millions they've collected over the years with their fraudulent copyright. While I can't believe any court will ever order Warner to pay the money back, there seems to be a pretty solid case that Warner can't claim the copyright any longer.
Really this is all just a somewhat updated version of what Marx called the primitive accumulation that preceded capitalism. While once people all more-or-less shared common spaces, eventually groups of power-hungry people decided to claim them as their own and declared they somehow now had the right to charge rents and exclude people from what was once communal property.
The whole Happy Birthday saga operates much the same way -- the tune had been a traditional one for a long time, and then eventually someone (it's still disputed who) put the current lyrics to it. More than likely, multiple people came up with the lyrics (not hard to see how many could have switched "good morning" to "happy birthday" all on their own), so it really never belonged to anyone. That of course did not stop Warner, who more-or-less just looked around and noticed no one was claiming the copyright, so much like the explorers of old, they simply planted their flag and claimed it as theirs despite having no hand in its creation.
It's the kind of thing that makes me wish I'd lived a couple hundred years ago -- apparently, you could just claim the rights to pretty much anything and then start charging people for using the stuff they themselves invented. Pretty ingenious move, capitalist scum...