Audible Matter / Wave #5 Sound September 2021

Harmonic Tremors

Manuela Ribadeneira

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Temblores armónicos

Manuela Ribadeneira's Harmonic Tremors is an insightful representation of her work on the uncertainties of the relationship between sound, scientific knowledge, and visual representation. Following a long-term research project inspired by her visit to Armero in Colombia, which was destroyed by the eruption of Nevado del Ruiz in 1985, Ribadeneira invited Pável Aguilar to ruminate on the three sonic phases of an erupting volcano. Out of Ribadeneira's recordings, Aguilar composed an orchestral piece, which we present here, alongside a conversation between the artists and Infrasonica.


Manuela, your practice observes the anecdotal and semantic level of objects concerning modern/colonial narratives, often from a practice that situates the intimate as locus. In 2016, you presented Temblores Armónicos (Harmonic Tremors), an exposition in FLORA ars+natura. You based it on research around volcanoes, initiated during your stay in Armero, on the eastern slope of Colombia’s Cordillera Central, devastated by an avalanche in 1985, which was a consequence of the eruption of the Nevado del Ruiz volcano. As part of the exposition, you invited the Honduran artist Pavel Aguilar to a collaboration where he created a sound piece: a haunting musical composition whose raw material is the sonic emission of the volcano. It’s interesting to note that the initial germ of this collaboration was the possibility of thinking from different territories and artistic methodologies. Perhaps it was a work about thinking together about the translation and sonic meaning of the volcano? Could you tell us a bit more about the development of this collaboration?

Manuela Ribadeneira

Hi, to respond to your question I should give some background about Temblores armónicos, my work with volcanoes and their sounds.
I created the first Temblores armónicos in the MAC Panamá as part of the LARA project between the end of 2017 and 2018. As you mentioned, it arose from my visit to Armero, which was destroyed by the lahars caused by the eruption. I had a vivid memory of that event, not only because I grew up and lived in Quito, on the slopes of the Pichincha volcano, but also because it was probably the first natural disaster that was experienced in this part of the world with the insolence and insistence of the television cameras invading the pain and horror of others.

What most impacted me about visiting Armero was not the destruction or the names of the owners of those ruins who in an act of possession and memory had been recorded. It was what I repeatedly heard during my visit and later in posterior conversations with locals: “This disaster could have been avoided because it was predictable.”

It pains me that the predictable is not avoided. We hardly listen and pay little attention to the ecological disasters we experience and the ballot boxes prove it. I ask myself, if we listened better and with greater attention, and if we believe in what we listen to, could we avoid disasters? (The title of the exposition in Casa Triángulo is called Ouca (Listen), and the subtitle for the exposition in FLORA was: Harmonic Tremors: Often a Warning).

I began researching the possibility of predicting the eruption of a volcano. I came across volcanic research in Alaska, Costa Rica and San Vicente. Scientists recorded sounds that are imperceptible to human ears until their frequency is changed. They discovered that there are three moments: the harmonic tremors, the cry of the volcano, followed by thirty seconds of silence before the eruption.

The process begins with an almost percussive sequence of sounds produced by an organ-like instrument or a combination of musical instruments played in very low frequencies (harmonic tremors). Then the frequency and pitch increase as the pressure builds. The tremors become smaller and occur more rapidly, eventually becoming a continuous harmonic tremor that is heard as a cry. When the frequency elevates to an absurdly high level, it produces a silence of thirty seconds. After the silence, the eruption.

Collaborating with Pavel arose from a request from José Roca to invite an artist in residence in FLORA to dialogue with me and my work. I chose Pavel because I was intrigued by his career as a professional orchestra musician. The knowledge that classical musicians have of interpretation felt very relevant to me. The classical musician knows how to interpret the music of others. Also, the idea of interpretation in relation to words caught my eye.

There is a difference that exists in the world of translation. The translator does their work by writing and with time. The person who translates simultaneously during a conference is not a translator but an interpreter. I imagined Pavel could be an interpreter of the sounds of the volcano. I was familiar with his previous work: transposing/interpreting well-known political speeches into the language of classical music. So I invited him to apply his interpretive technique to the recorded sounds of the volcano. The interesting part was that the result was simultaneously more listenable but also more cryptic. It was a step removed from the volcano but perhaps emotionally closer.

There is another reason why I invited Pavel to work with me: Silence. It is one of the most important moments before a volcano explodes. I was “burdened” with John Cage and the ways there are of speaking about silence in the histories of art and music. Then I saw on the table of Pavel's workshop a small sheet of paper where he had scribbled the bar of a score and it was simply a musical silence. I am lucky to have that sheet of paper with me!
For the exposition at Flora, Pavel made a version of that same piece on die-cut paper, that is, silence on emptiness. We called that piece: Often a Warning.

Pável Aguilar

When José Roca introduced us, we immediately had excellent energy to work together, without having a precise idea of where to begin. The invitation to collaborate and propose an extension of Temblores Armónicos by an artist as outstanding as Manuela was a welcome challenge to my creative process. Common concerns about the power of silence and my work linked to the visual abstraction of musical sounds were the connecting threads that articulated our proposal.
Exchanging ideas and having results that four years later are still generating interest gives me great joy.

Thinking of a proposal for a sound interpretation of the volcanic phenomenon was fascinating since we worked with rhythmic and sound patterns imperceptible to the human ear. It was a new experience to study volcanic sounds because we do not have active volcanoes in Honduras or even records of disasters caused by them.
However, the context and root of the project were familiar to me, since in the Central American region it is, unfortunately, a sort of perverse norm to gather all the possible options on "how a natural disaster could have been avoided", added to the media's yellow journalism that further exposes the vulnerable condition of the affected people.

Working with such an atypical sound base was a challenge because it was not possible to alter the tones of the original sound. This would have caused a difference with the nuance of the eruption process and the movements of the original composition, authored by the volcano where I was its "sound interpreter."
Each of the sounds interpreted on the piano has the exact tonal pitch of the extract from the recordings made underground. Through a classical musical composition process and the help of specialized software, they were interpreted into a score.
I decided to work and interpret using piano scores as its the most complete instrument in terms of amplitude and body. It was useful to work with the recordings which, in this case, were made using subterranean microphones.
Another interesting part was to make recordings in English, Portuguese and Spanish of sound interpretations with our voices. Manuela in London, Rodrigo Editore (her gallerist in São Paulo) and myself from Bogota made a micro-collection of words and emotions that arise when witnessing a natural disaster.
In short, more than having collaborated with Manuela, the process motivated interests and phases of experimentation still alive in my work, all thanks to the “great power of silence” and those harmonic tremors.


That game with the recorded words to relocate to the language of classical music was the first time that I worked with QR codes, then little-known and today, thanks to the pandemic, everywhere. I love them because they are mini containers. In our piece, they contained short musical phrases, the translations into a classical musical language of the words related to the eruptions, to fear.

I always wonder how the public saw or experienced this piece. In part, I am not sure that it quite worked because the QRs were not familiar and people did not know what to do with them. Today, the piece would be different, without the need for instructions, people would activate the QRs and perhaps create a symphony, cacophony or sequence of words in a spontaneous manner.
It was important to me that those words or mini phrases appeared on the bulletin board at FLORA. I wanted them to be small alerts. Not as large as warnings, but notices or reminders.

I don't know what you think, Pavel, but somehow the translation into classical music of these words or phrases softened their meaning. Do you think it's an aestheticizing process?


The interpretation of our voices and their translation into musical scores, I feel, encrypted their meaning but kept the sense of alertness and fragility more poetically, keeping the "fear" in each mini-composition. I especially remember the phrase ¿Tienes miedo? (Are you afraid?) with our voices and their musical interpretation.

Also, the task of interpreting each of the phrases that the three of us shared between Bogotá, London and Sao Paulo produced the same effect of interpretation and composition as the volcanic eruption. Maintaining the intention and strength to transmit that same energy through musical notes had multiple readings by the audience and I think about how foreign and distant 2018 feels in comparison with the fragile beginning of this new decade with the pandemic.

I would be fascinated to repeat this exercise again in our current times. Hopefully, we can meet again soon.

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