2014 | 12'
ensemble and electronics
fl, cl, sax, vl, vc, pf, perc, 2 ad-hoc players 
4 trumpets, moiré-instrument, keyb, video

Constructed Nature

Human beings are stereo machines. Most of our perception is based on correlation strategies. The distance between your eyes causes a shift between the two images, which is encoded as depth. The separation of your ears results in a short delay, a phase shift unperceivable by your naked ear. Yet this phase-shift is responsible for your spatial hearing. The supperposition of the signals from both ears creates an interference pattern, which is encoded as the angle of the sound source.

In moiré the ensemble is divided in two groups. The source group plays sounds which are routed to the filter group, which modifies them. The filter group consists of a moiré-instrument and two waveguide instruments. Both instruments are based on the principles of binaural hearing. In the moiré instrument, two sheets with regular patterns are supperposed to generate a visual interference driving a series of light  sensors (dark regions block the sound, bright parts amplify it). In the waveguides, interference takes place when sound is mixed with a copy of itself after having gone through the tubings of a trumpet. By operating on the valves of the trumpet, the space separating the source from its delayed copy is modified: some frequencies are reinforced, other dissappear.

In both cases, space becomes audible as timbre.  The patterns, which we perceive as "colors" are what enable your sensory system to assess the space around you. With this constructed nature we want to underline that perception is your first media experience. 
NB: the audio quality in this video is not satisfactory. It has been uploaded to serve as a documentation of the visual aspect of the performance.

Waveguides

​A waveguide is basically a narrow tube. In this case it is formed by two  trumpets connected in series. Sound is delayed by purely acoustical means, routing it through a series of tubes, and then mixing it together. This creates a very specific kind of interference pattern, known as a comb-filter. This is the exact kind of interference present in your own ears. The main difference is scale: our waveguide is the equivalent of a head up to 200 times bigger than yours. 
Picture
Sound enters the instrument through a mini speaker (A). It goes through the tubes depending on which valves are open and is picked up by a microphone. Original and delayed sounds are mixed together and sent to a speaker.

moiré instrument

​The moiré instrument consists of two transparent sheet with the same regular pattern printed on its surface. Multiple light sensors react to the interference pattern created by the transparent sheets: sound will go through in the bright regions and will be dimmed in the dark regions. Each sensor is wired to a loudspeaker, so movements in the interference pattern are reflected as movements in space.
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