Why you can’t get a song out of your head

The aha, in writing

1. Researchers asked three thousand people which songs had got stuck in their heads.
2. The same kind of song kept coming up: bigger chart hits and more recent ones were named more often.
3. Compared with similar songs that never got stuck, the earworms were faster, with a familiar overall melody shape and a few unusual steps inside it. That is one study, so it is a clue, not the last word.