Oskar Fischinger- An Optical Poem (1938)

Oskar Fischinger is known for his animations of sounds. This piece starts out with each note starting out as different sized circles depending on their volume, and each fades into the distance, getting smaller, as the note fades and gets replaced by other notes. Different sounds or instruments seem to be represented by different colours and shapes. The strings at the start are circles, whereas later, the woodwind sounding instruments are squares and lines.