CHORA

The Chora piece was developed as a way of visualising the intrinsic order and archetypal properties that lie within the phenomena of sound and providing a measurable technique for considering the effects of sound fields on objects and spaces. The title of the work refers to the ancient Greek concepts of both chora and chorus. In this project the term ‘chora’ was considered as a space from which the idea of form can be manifest, a receptacle for the genesis of the concept of spatiality that forms the foundations of the attributes of place and place making. These allusions were integrated with the idea of the chorus in traditional Greek theatre, in which a group of performers would use vocal techniques such as synchronization, echo and ripple to provide an accentuated aural layer of commentary to the unfolding drama onstage.

With these influences in mind, Chora was conceived as a sculptural vocal choir that could adapt its output and spati al arrangement in response to different environments, circumstances and moods to create unique spati al aural events. Rather than being a musical piece or non musical soundscape, the Chora is based around the conception of a composition of carefully tuned tones and their interaction with specifically dimensioned forms so that they create tangible and specific spatial sensory affects. In this way the work was conceived as a way of matching the arithmetic, geometric and harmonic aspects of sound fields, sculptural forms and their surrounding space.

The concept for the tonal system that interacts with the Chora piece was based on the diatonic scale (which correspond to the white keys on the piano) these musical notes were chosen as their wavelengths have a direct proporti onal relati onship with one another. Initi ally the concepti on of the piece was based around Pythagorean tuning, in which multi ples of the 3:2 proporti ons of the perfect fifth were used, to create a fractional system for the understanding of specific notes and their relationship to specific lengths of hollow cylindrical forms.

The visualisation of this concept highlighted the idea that it is possible to produce a number of different resonant frequencies, harmonics and overtones with air columns within the specific length of tubes and in doing so create an array of potential harmonic juxtapositions. It was envisaged that the individual columns would resonate with the tones of musical scales, creating multiple harmonic arrangements between the carefully tuned chambers. In order to achieve this, research was done to ascertain the absolute lengths of specific musical notes in both open ended and closed volumes which in turn informed the calibrati on of lengths of cylindrical pipes used in the design of the final piece.

The study of the dimension of sound waves led to the generation of a series of sculptural forms that employed specific horizontal tube lengths so that complimentary harmonic relationships between two notes could be employed to resonate within them. These columns were punctuated by a smaller intersecting tube that acted simultaneously as: a device for the modulation of specific resonant frequencies of the tube; a base reflex vent that improves the efficiency of the air column at low frequencies; and a listening portal from which an inti mate experience of the sound produced within the chamber can be heard.

The installation was made up of three column-like forms that are laid out in plan on the points of an equilateral triangle. The standing columns were of diff erent lengths and the portal tubes intersect them at diff erent heights relative to dimensions of the notes which will play through them. The outer skin of the column forms were abstractly reminiscent of the human figure, the different ratio of the wavelength columns giving each individual figure its own slightly different personality. The idea that the arranged objects were members of a chorus was heightened by the human sounding tones that resonate from deep within the standing sentinels.

 

In this sculptural/spatial/harmonic composition, the precise distance between individual sound sculptures was considered as being essential so as to set up the optimal relationship between sound sources for the creation of clearly defined patterns in the acoustic fi eld. The geometric interaction of the sculptural forms and the patterns of sound that they generate, orchestrates the experience of the space which surrounds them.

These concepts were first visualised through the construction of a series of drawings/diagrams that sought to map the nature of the interference patterns that the arrangement of forms and notes would possibly create. These diagrams not only became an important tool in the conception of the potenti al soundscape in a visual and spati al way, they were also particularly informative in the way they expressed the intensities and dispersions of the sound field.

Through the gestalt of the visual patterns generated, the diagrams acted as a way of illustrating how the mixing of nodes and anti nodes creates various amplifications, cancellations, beats and composite affects within the sound field. The diagrams also highlighted the need for a degree of acoustic isolation of such a sound field, as its affects work more clearly as one enters the perimeter of the resonating forms but could be destroyed by reverberant conditions of the surrounding space.

Through these considerations it became clear that the relationship between a carefully composed sound source, its qualities when interacting with resonant sound sculptures and the acoustic conditi on of the space it is situated within, is a symbiotic interaction in which all elements need to be considered and finely tuned.