Earworms: Those songs that get stuck in your head

Have you ever been waiting in line at the grocery store, innocently perusing the magazine rack, when a song pops into your head? Not the whole song, but a fragment of it that plays and replays until you find yourself unloading the vegetables in time to the beat? Elizabeth Hellmuth Margulis explores earworms — a cognitive phenomenon that plagues over 90% of people at least once a week.