FISHING FOR RESONANT FREQUENCIES (sound and architecture)
by Gustavo Matamoros

There is an entertaining way of fishing resonant frequencies in an architectural space. Take a microphone, connect it to an amplified speaker and move it around the room until you hear feedback. The tone you hear comes out of thin air and defines in sound a particular architectural feature of that space. Change the microphone’s position and you may find another tone.

I learned this from my long time friend, colleague and mentor, composer and sound installation artist Russell Frehling back in the mid 80’s. The use of resonant frequencies is a major component of his compositional strategy and a technique I have often used since in my own site-specific work.

Using helium-filled balloons (or in the case of Russell’s Mapping, a radio controlled blimp) and a wireless microphone, makes it possible to fetch resonances in high places – like the courtyard at Vizcaya.

Tuning sounds to these found frequencies and playing them back into the room creates the kind of uniquely fulfilling sonic experience for the listener typical of this kind of work. Resonant Frequencies are part of what Russell defines as the “acoustical signature” of a space. I think about them “being right at home”, and therefore excellent tour guides in their aural description of the surroundings.

Because the resulting tones respond to the architecture, they often don’t coincide neatly with those of the tempered scale of whole tones and half steps we’ve grown accustomed to in Western music—which in modern times uses 440Hz as a reference frequency for the note A.

I have found many spaces that contain microtonal sonorities that are seldom found in traditional music. What strikes me the most is the way these otherwise out-of-tune tones tend to get along so well with one another as they occupy their physical space of origin.

Gustavo Matamoros
June 21, 2006