The underlying Happy Birthday melody is the traditional birthday song sung at celebrations for generations, but this weird version comes from the internet habit of remaking familiar songs in intentionally bad, off-key styles for memes. Short, distorted covers like this spread through soundboards and short video edits because the joke is instant, even without context. It remains popular for ironic birthdays, fandom edits and joke greetings where a normal, sincere version would be too predictable, and the strangeness is exactly the point of the celebration.