„Sometimes it is useful to see an organism, even man, as a self-preserving mechanism“, claims biologist S. Anthony Barnett. „Regulation depends on change, especially change in behaviour. What is more, a person is no machine. People have their own will.“ This sentence forms the basis of „middle high tones“ by Brazilian artist Cristian Duarte. And he reacts with uncomfortable questions: What are the limits of human autonomy? And what is the difference between walking and being walked? The result is a discerning work, lucidly structured and full of ironic sensitivity, with a tender off-voice and music by Ricky Martin, Kylie Minogue and Leonhard Cohen.