Why we really really really like repetition in music

It slays all day. In episode #5 of Vox Pop's Earworm, producer Estelle Caswell, comes to appreciate the art of repetition with the help of Colin Morris and Elizabeth Margulis. Colin is a computer scientist who created two really amazing ways to visualize repetition in song lyrics and how they've increased over the last 50 or so years.
Gary White