Aura Calculata, challenging the tonal scale


An unlit space is illuminated by a pataphysical construction composed of a circle of neon-lit liquid acrylic tubes. Electrical clicks pulse the neon illuminations on and off in precise synchronisation like a secret code of intercommunication. The contraption’s occluded transactions are scored by a series of sinuous pipe drones. The sporadic clicks provide a necessary percussive punctuation to the organic drone. The machines autonomy – its ceaseless self-adjusting mechanisms – its obsession with its own functions – intimates a sense of self-knowledge and self-awareness. The idea of imparting sentience to automata is an age-old trope, but a resurgence has emerged in contemporary robotic sculpture hedged on by current preoccupations with artificial intelligence. Aura Calculata by Tim Otto Roth works by allowing water to flow into the sculpture through a series of valves to enter each acrylic pipe. A liquid equilibrium is reached as all pipes contain an even distribution of water. But the pipes are further connected by a network of electric cables allowing each to communicate their states between one another. The mode of communication is based on a rule of simple neighbourhood interactions similar to the way Cellular Automata work. Cellular Automata, such as the famous Conway’s Game of Life, operate by having local interactions of individual agents creating much larger macroscopic patterns. Though CAs are defined by abstract mathematical rule-sets there are many analogues that can be found in nature. The canonical example of this kind emergent behaviour – global structures generated by local agents – are the mounds created by termites as they go about their business often oblivious to the precise form of structure they are creating. In the case of Aura Calculata the global state is expressed by the tones of the organ pipes. In this sense the piece is a sonification of local agents creating global structure. As air streams through each pipe a note is generated related to the level of water. As the communication between pipes develops, the levels change and consequently the pitch and timbre of the notes change too. To begin with, the level of water is equal in each. This produces identical tonal and timbral characteristics. But as the relative levels begins to change microtonal differences in the notes begin to emerge. As alien Aura Calculata is to a standard church pipe organ, visually and conceptually, it is as different from the dominant western musical scale too. Aura Calculata challenges the hegemony of the Western tonal scale because the wavelength of the sine tones are varied metrically as opposed to logarithmically. This generates much smaller, nearly imperceptible microtonal changes in lower tones, and much bigger differences in the higher ones. Paul Prudence


aura calculata (2016) – a self-organizing water organ by Tim Otto Roth