Feedback Systems

“ You can’t totally control noinput music because it’s all about feedback. Things like turning the tuning knob, even by one millimeter, make a big difference to the sound. …It’s very hard to control it. The slightest thing can change the sound. It’s unpredictable and uncontrollable. Which makes it challenging. But, in a sense, it’s because of the challenges that I play it. I’m not interested in playing music that has no risk. “ (Toshimaru Nakamura)

Reading a paper on feedback systems, from Dario Sanfilippo and Andrea Valle: “FeedbackSystems: An Analytical Framework”, I found interesting a given key to understanding feedback itself and the relation between the different parameters. Specifically I focused on a paragraph that emphasizes the non-linearity of a feedback system and how different sonic parameters, normally unrelated in an audio system, are actually related to each other.

As they mention in the paper, parameters like amplitude and pitch, are coupled in a condition where they mutually affect each other in an interaction system. Their combination is leading to new entities that are not the summation of their parts, instead a new element that coexist only because of their synergy. Each element has its own identity, no one has the role of coordinator, but all play as equals to achieve a goal that takes shape only through their essential cooperation. This is also resembled in the loose relations of non- or flat hierarchical organisations, where each participant´s ideas are equal to and influence each other. The emerging results are unpredictable to a certain degree.

Inside this process, the smallest changes of one parameter or in the setup influences the overall result unproportionally. Therefore it´s difficult to reproduce the results although it´s possible to train playing it as an instrument, to attain a certain amount of control. By testing the influence of different parameters, you can understand roughly what a single parameter/event changes in the whole system.

It is important to underline that every performance is unique and you can´t know before if it´s going to be a success or a failure. Each setup is unique in its possibilities, even using the same gear never sounds identical. Still a sort of connection between the sonic phenomena and the interaction with the performer within the system is achieved, which´s framework is outlined by the composer.

In contrast to playing a conventional instrument, the performer and system meet equally as agents. The performer interacts within a complex net, changing the dramaturgy of the sound itself. Sound and form are not to be differentiated, the concept of coherence depends on the level of understanding the immanent evolution of events and their relation to each other.

Feedback offers great variety of different possible results from seemingly chaotic to minimalistic. Thanks to its flexibility, it is usable to explore these extremes in a continuum. The risk of loosing control becomes part itself of the compositional process, if on one side the indeterministic behaviour puts you on a subordinary position, on the other side feedback systems tend to stabilize themselves giving you the possibility to explore the potential of this unstable “holy” dimensions.

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