Toshiya Tsunoda has long been revered for his meticulously detailed recordings of acoustic phenomena both in field or natural settings and in constructed atmospheres. Tsunoda?s particular interest is in how acoustic forms mutate either in contact with closed resonance chambers or with various editing techniques. Often the outcome of these experiments is that structure present in the original sound source is echoed in larger resonant areas. Because of this echoing of structure at different scales, it is tempting to employ a fractal metaphor to describe Tsunoda?s output. However, this is not exactly apt because fractals are mathematical formulae that reproduce structure recursively, in the absence of external stimuli. They are self-contained, not interactive.

As if in a winking refutation of a pure fractal analysis of Tsunoda?s work, the cover art for ?Ridge of Undulation? features Afsuo Ogawa?s beautiful renderings of fractal-like drawings. Rather than mathematically generated pictures of fractals, the freehand pictures approximate this geometry while still maintaining a freedom from the completely formulaic. Tsunoda is clearly very much at home in this nebulous region between structure that can be observed and that which can be made. As is his wont, he has divided the tracks on ?Ridge of Undulation? between site-specific field recordings and elaborately constructed micro-acoustic environments featuring layered sine waves and vibrating plates. Beyond the layering on two tracks, very little editing has been done aside from some volume adjustment. All of which only makes the results more astonishing. For whether he is generating or capturing it, Tsunoda?s organic and inorganic uses of his sources makes him seem to be sketching in thin air using sound as his charcoal.

Through careful editing, Tsunoda can make field recordings sound artificial (e.g. the lock-groove loops within ?Seashore, Venice Beach? that are achieved apparently only through volume editing). Thus, he conflates any ?essential? difference between the ?natural? and the constructed. At the same time, his prepared sonic environments are so closely monitored and manipulated that they approximate and extend effects heard within the field recordings. For example, ?An Aluminum plate with low frequencies 1? follows directly after the Venice Beach track and sounds like the wind coming in off the ocean at that location, perhaps as heard from under the tide itself. Later in the disc, ?Arrival, Kirarazu bay? could just as easily be the soundtrack to a starship docking as doors open and close against an engine?s whining background drone. There is so much selectivity at work on the source acoustics in this piece that when the second aluminum plate recording follows ?Arrival? by distilling the engine?s tonal variance in a plate vibration, it ends up becoming a continuation of the previous piece?s focus on the engine. When a thin plate properly vibrated can emulate a portion of the spectrum of a larger environment, the recordings themselves seem to converge at a vanishing point between the consumption and creation of sound.

While this convergence could itself be fodder for hours of acoustic studies, Tsunoda also finds time to create mini-narratives. ?Metal pieces with high frequencies? is the final Morse code escaping from an exploding supernova before everything goes white. ?Sine waves mixed with the sound of a vibrating surface 1 and 2? show how much potential is contained in a pure tone as the resonances generated from the tones are then mixed back with the original tone and additional waves. Pulsating, ringing and disorienting in its recursive layering, yet continually compelling, this kind of work makes one believe that alien landscapes could be discovered on the head of a pin. If they are there, then there are good odds this remarkable artist had a hand in their creation. 9/10 -- Steve Rybicki (27 June, 2006)