Imagine the brain's delight when experiencing the sounds of Beethoven's "Moonlight Sonata" while simultaneously taking in a light show produced by a visualizer. A new study did more than that. To understand how the brain responds to complex auditory-visual stimuli like music and moving images, the study tracked parts of the auditory system involved in the perceptual processing of "Moonlight Sonata" while synchronized with the light show made by the iTunes Jelly visualizer.