"Geometry of Circles" is a short form animation created in 1979 by none other than the musical mind of Philip Glass for Jim Henson's Sesame Street. We are hard pressed to think of a better collab. 

Designed as a primer for visual thinking — "Geometry of Circles" weaves Cathryn Aison's hypnotic graphic illustrations with Glass’ ambient musical compositions, creating a beautiful synesthetic visualization of the music. Inspiring for young and old alike, we could watch for hours.