On 29 November 2011, the audience heard Lloyd's sonifications while simultaneously watching the brain activity that generated them and the stimulus film that generated the brain activity.

Music of the Hemispheres creates a feedback loop of consciousness and perception: Chavez is composing and performing a self-portrait of her consciousness that the listener-viewer perceives.

What can this concert-film tell us about spectatorship? A neuroscientist can derive more nuanced information from these sonfications and visualizations, but even a casual observer can see that listening to actual sounds generated more brain activity than imagining sound. In Chavez's brain, listening to Einbond's composition generated more activity than listening to sounds of rain; in Antoniadis's brain the opposite was true. Both subjects responded more to the appearance of a face than to a gray screen. The image of their own faces generated more brain activity than the image of Einbond's face. Certain people respond more to soundscapes they have to interpret while others respond more to a finished composition. There are limits to what the untrained eye can conclude: although Chavez appears to take several seconds to respond to the appearance and disappearance of her own face, this is actually a function of the time it takes the fMRI machine to register the blood-flow in her brain -- which Lloyd has not corrected for in this video. Nonetheless, we can see and hear how spectators respond in real time to what they see and hear.

Obviously we need more -- and more detailed -- information before this approach can begin to be of practical use to neuroscientists, artists, and theorists, but it is a beginning. It paves the way for new ways of thinking about spectatorship that will be useful to scholars and practitioners in all the fine and performing arts, as well as to neuroscientists and psychologists. Perhaps the most important contribution this concert-film-experiment makes to our understanding of spectator response is that we no longer have to guess at what spectators respond to. Nor do we have to work with a theoretical model of spectatorship derived from print culture.