In e-mail correspondence with an overseas contact, whose native language is not English, he asked at one point "What is an 'earworm'?" Well, of course, I volunteered to provide an example! As a matter of fact, it's one I blogged about in 2015, when I first encountered it. (The comments at that earlier blog post are worth reading, too.)
At any rate, here's Austrian "DJ Ötzi" with his (in)famous "Burger Dance", which went gold in Germany and hit #1 on the charts there (why, I don't know!). His teenybopper audience appear to be singing right along, and getting into the spirit of the thing.
If that isn't the living definition of an earworm, I don't know what is! The song was written by the British group Fast Food Rockers, who called it simply the "Fast Food Song". Their official music video may be seen here. However, I prefer the Austrian version, for some weird reason. (Perhaps it's the "Rocky Horror Picture Show"-style pelvic thrusts from the dancers? I still can't figure out how they go with any of the restaurants named . . . at least, I've never seen diners there perform them!)