How many times does the chorus repeat in your favorite song? How many times have you listened to that chorus? Repetition in music isn't just a feature of Western pop songs, either; it's a global phenomenon. Why? Elizabeth Hellmuth Margulis walks us through the basic principles of the 'exposure effect,' detailing how repetition invites us into music as active participants, rather than passive listeners. [Directed by Andrew Zimbelman, narrated by Addison Anderson, music by Joshua Smoak and Alex Admiral Collier].