Why do songs get stuck in your head?
Catchy songs with simple, repetitive melodies tend to loop when your mind is idle. Researchers call them earworms, and almost everyone gets them.
Going deeper
Earworms often show up when your brain isn't busy, like while walking or doing chores. They're usually a short fragment, often the chorus, rather than a whole song.
Studies of the catchiest songs suggest they share some traits: a fairly fast tempo, a simple melody shape and an unusual interval or rhythm that makes them stand out.
To get rid of one, some people listen to the whole song through, or give the brain a moderately hard task. One study even found that chewing gum reduced them.