The word syntony means collective behavior resulting from the locking together of frequencies. It is a phenomenon of resonance, and is present in many biological, physiological, and social phenomena. Here Syntony is explored through a self-organising installation made up an ecology of robotic performers that communicate sonically with each other. Each autonomous machine has two rotating parabolic dishes, one that projects directional sound into its environment and the other that listens for its neighbour’s signals. Syntony is inspired by the cybernetic machines of Ross Ashby’s Homeostat and Gordon Pask’s Colloquy of Mobiles, where decentralised stability can emerge from the interaction of many independent adaptive machines. Syntony, an inhabitable environment, allows people to enter into the ecology and interact with the communicating objects, interfering with the sonic networks of exchange, triggering recombination and generating new sound landscapes. 4 Syntony Machines are presented here as a study similar to Ashby’s original Homeostat experiments. We believe much larger adaptive sonic networks are buildable.