The song that everyone knows

Every culture has songs that nobody remembers learning. You did not sit down to study them. They arrived during childhood through repetition, and they will still be in your head in sixty years when far more recent things have gone.

Researchers who study memory find this unsurprising. A song combines several things the brain holds well: a melody, a rhythm, a rhyme scheme, and a strong emotional setting. Each of these is a separate route to the same memory. Forgetting a plain list requires only one route to fail. Forgetting a song requires several to fail at once, which is why people with serious memory loss can sometimes still sing songs from their childhood after they have stopped recognising faces.

This is also why songs were used to carry information before writing was common. Long poems, legal rules and genealogies were set to rhythm and rhyme because those features make errors noticeable. If a line is misremembered, it usually stops scanning or stops rhyming, and the mistake announces itself. A prose sentence has no such alarm.

Teachers of foreign languages have rediscovered this repeatedly. A phrase learned inside a song is held longer than the same phrase learned from a list, and the effect is largest for the parts of language that are hardest to learn deliberately — rhythm, stress, and where the voice rises and falls.

It is a strange arrangement. The brain treats a tune as more worth keeping than a fact.