An ecological acoustic perspective also takes into account all the information about how the sound is perceived in the environmental space. In any amplified context the use of microphones alters the usual perception of both the quality of the instrumental sound and its projection in space. These two aspects are usually taken into account, considering on one hand the already mentioned filtering that any microphone – even the most hi-fidelity one - adds to the instrumental sound quality, and on the other hand how sound is projected in the space through loudspeakers. Their use implies dealing with multiple variables, such as their frequency response, their number and disposition, and their relation to the acoustic responses of the room. All these variables also affect the perception of the distance or closeness of sounds in the space. Finally, it has to be considered that the acoustic instrument itself constitutes a sound source, so the amplified sound projected in the room through loudspeakers adds to to the actual instrumental sound.
All these general considerations are at the basis of any work involving forms of amplification. Even more so in the specific case of my research, which deals with a peculiar form of amplification. As already discussed, the use of piezo enables a form of mediate listening, which demands a strong engagement with different aspects of listening, raising several questions:
- How does the use of piezo interfere with a usual perception of the amplified instrumental sound and of its projection in the space?
- Which kind of listening situation should I foresee in order to allow people to clearly perceive a different proxemics of sound?
- Is space a compositional element?
The hyper-amplification of the instrumental matter through piezos provides a significant shift from the usual auditory feedback. Using piezos implies the most close-miking technique, which picks up the sound of the instrument directly from the vibrating surface of the instrument, isolating it from other sound sources, and minimizing the ambient sound. Moreover, due to their very specific acoustic properties (as already explained in chapter 2) piezos filter the instrumental sound, conferring on it a very peculiar colour, while clearly revealing the sonic presence of the technological tool between the acoustic sound of the resonant object and the human ear. So, the instrumental sound matter amplified and produced with the piezo gains a new sense of proximity. This term has the same root as the word "proxemics", which refers to the study of the human use of space within different cultural contexts. This term was introduced by the anthropologist Edward T. Hall. In his essay The Hidden Dimension (1966) Hall developed a theory of proxemics, arguing that human perceptions of space, although derived from sensory apparatus that all humans share, are culturally patterned. Hall observed how different cultural frameworks for defining and organizing space are internalized at an unconscious level, and they can produce misunderstanding within communication in cross-cultural settings. In a similar way, I would argue that the perception of amplified instrumental sounds is internalized at an unconscious level according to a few constant aural habits. The way piezos amplify instrumental sound creates a moment of disruption in this usual perceptual pattern. This uncommon sense of proximity means that the sound produced with piezo is perceived as strikingly close, generating a different proxemics of sounds. Fig.3.3.1 shows bb.198-200 of Residual, a piece for ensemble and electronics, in which the cello performs an action involving the piezo.
During my work with piezo, this aspect leads me to try different strategies in order to highlight the sense of intimate proximity and the actual changes in the proxemics of sounds. I want to refer here to two different pieces that enacts quite different strategies: Residual for ensemble and electronics, and PianoMusicBox_1, for piano and electronics. These two pieces present different situations in terms of the kind of amplification and the strategy chosen to project the amplified sound in space.
Residual was commissioned by Hermes Ensemble, and premiered at the Concertgebouw in Bruges, on November 21st, 2019. With this work I have worked with space at a compositional level, exploring the possibility of working on two different planes of sound: one in the foreground, and the other in the background. The cello and the percussion (timpani, marimba, güiro, crotales) are the instruments in the foreground, which act almost as soloists. The cello is provided with one piezo, which has to be used to play different gestures on the instrument, and another which has to be fixed on its body with the purpose of amplification. Concerning the percussion, one piezo has to be fixed on the surface of the timpani, another on the lowest C-key of the marimba and a third has to be used to play the crotales and the güiro. Both percussion and cello are primarily amplified with piezos, although a condenser microphone is added, in order to smooth the color of the piezo. The rest of the ensemble – flute, clarinet, violin and viola – is arranged in a semi-circle behind the soloists and is amplified only with a pair of condenser microphones, with a sort of transparent amplification, i.e a light reinforcement of the instrumental sound. In order to emphasize the perception of these two different planes, cello and percussion are amplified through their own loudspeakers, placed next to them. In this way, both the sound of the acoustic instrument and its amplification are projected in the space from almost the same spot. The rest of the ensemble is instead amplified through a pair of stereo loudspeakers placed behind the ensemble (fig.3.3.2).
The piece articulates a catalogue of actions and gestures that explore different degrees from almost pitchless to more pitched sounds, sometimes using the sound quality of piezos in order to create similar sounds for the cello and the percussion, as happens, for example, in the first section of the piece. Here the percussionist starts playing on the surface of timpani with a gentle scraping sound, using fingers or nails. The cello enters after a few bars with a rhythmic counterpoint of actions, playing with the bow next to the piezo, which is placed flat on the string in a determined position, producing a quite airy sound that resembles the one of the timpani. A quite unstable and unpredictable materiality of sound emerges from the gestures played with piezos. A similar instability is sought in the sound quality of the ensemble, especially when using harmonic sounds of the strings and airy or multiphonic sounds of the woodwinds.
In the last sections of the piece, the piezo-sounds of cello and percussion are processed electronically. The processed sound is sent to the main loudspeakers, instead of being sent to the more directional loudspeakers of cello and percussion. In this way the electronically processed sounds are clearly distinguishable from the “acoustic” piezo-sounds, and their foreground-quality enters in the background sound plane.
Instead of seeking to highlight different sound planes, foregrounding the different proxemic of piezo-sounds, PianoMusicBox_1 aims to concentrate on the inner sounds of the instrument and its hyper-materiality. PianoMusicBox_1 has been written for and in collaboration with the pianist Chiara Saccone, and it was premiered during the festival “Collaborations are More Refreshing than New Socks”, at the Royal Conservatoire of Antwerp, on December 4th, 2019. The amplification strategy includes the use of two piezos – one is given to the pianist for the production of sounds and the other one is fixed on the soundboard, providing information to the electronics. The first piezo produces sound while amplifying – and sometimes as input to the live-electronic processes. In addition to the piezos, two transducers are placed inside the stringboard of the piano to create a closed system, in which both the acoustic instrumental and live-processed sound are amplified through the body of the instrument. In this way the piano becomes the only sound source. (In the case of performing the piece in a very big room, a couple of microphones and a stereo set of loudspeakers might be used to reinforce and better project the sound of the piano in the space (fig.3.3.3).
The piece starts with a few gestures, produced by exploring the inner part of the instrument – the soundboard and the strings – with the piezo. The pianist operates different gestures of gentle scraping and glissandos along single strings, or with transversal movements on a certain range of strings, or behind the bridge. In the first sections of the piece sound matter always results from the direct contact of the piezo on the string. The materiality of the string emerges clearly. Part of this sound material is recorded through the piezo and it is then played back as it is or after undergoing processes of filtering and granulation. The aim is to enact an intertwined internal dialogue between the processed sound and the live one produced by the pianist. Both layers of sound share similar acoustic features.
In this section, the piezo has to be placed flat on the indicated string, in the position more or less corresponding to the head of the note, here replaced by the straight line. The piezo here has a double function: it tunes the string – as a finger would have done –, and it closely amplifies the movement of the bow. The emergent sound quality is extremely airy, except for the moments in which the bow moves toward the bridge, the pressure increases and the dynamic grows significantly. Here the sound becomes extremely complex and noisy. During one rehearsal I have made a recording of these few bars, both with piezo only and with condenser microphones, which also capture the environmental sound. Comparing these recordings it is extremely clear how close and hyper-real, the piezo sound appears (audio ex. 3.3.1a – audio 3.3.1b).
Moreover, both come out from the piano through the transducers, sharing the same sonorous space. In this way, the perception of dealing with the same sound instrumental matter is reinforced. The listener's attention is so drawn to the same complex and intimate sound world. Only gradually does the pianist reach the keyboard and the piece moves toward a more familiar piano sound-world, but the feeling of proximity and intimacy is maintained by the same colour of the amplification through the piezos and the transducers.
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