Why Songs Get Stuck in Our Heads
Almost everyone knows the experience. You hear a few seconds of a song in a shop, and for the rest of the day the same chorus plays in your head, again and again, whether you like the song or not. The experience is so common that it has an informal name: an "earworm".
Earworms seem to have a few things in common. They are usually short pieces of a song rather than the whole thing, often the chorus. They tend to be simple and repetitive, with a melody that rises and falls in a way that is easy to sing. And they are often songs we have heard many times recently, which suggests that repetition makes a tune more likely to return.
Interestingly, earworms often appear when the mind is not busy. Many people notice them while walking, showering or doing a routine task. One explanation is that the brain, when it is not focused on anything demanding, tends to replay recent and familiar material. A catchy chorus is perfect for this: it is familiar, it is short, and it feels unfinished, so the mind keeps returning to it.
That unfinished feeling may also explain one of the most popular pieces of advice for getting rid of an earworm: listen to the whole song from beginning to end. Some people find that completing the song helps the loop stop. Others prefer to distract themselves with a task that needs real attention, such as a difficult puzzle or a conversation. Chewing gum is sometimes suggested too, perhaps because it interferes with the small movements of the mouth that we make when we silently "sing" along.
For most people, earworms are a harmless and even slightly funny part of daily life. They are a reminder of how deeply music connects with memory, and of how much of our thinking happens without us deciding to do it.