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the love of sound
Ambient Sound and Resonating Spaces - Rob Godman


What is ‘ambience’?
• atmosphere
• feel
• environment
• mood
• quality
• character

What is ambient music?
So just who was responsible for the idea of ‘Ambient Music’? Well, depending upon which book you read or which CD cover you gloss over you may well find yourself coming up with the answer of Brian Eno. Whether or not you believe this to be fact or fiction it is still worth reading a couple of Eno quotes: -

"Ambient Music must be able to accommodate many levels of listening attention without enforcing one in particular; it must be as ignorable as it is interesting."

"My friend Judy Nylon visited me and brought me a record of eighteenth-century harp music. After she had gone, and with some considerable difficulty, I put on the record (Eno had just been released from the hospital and was bedridden). Having laid down, I realized that the amplifier was set at an extremely low level, and that one channel of the stereo had failed completely. Since I hadn't the energy to get up and improve matters, the record played on almost inaudibly. This presented what was for me a new way of hearing music-as part of the ambience of the environment just as the colour of the light and the sound of the rain were parts of that ambience. It is for this reason that I suggest listening to my pieces at comparatively low levels, even to the extent that it frequently falls below the threshold of audibility."

There have been others before Eno who were producing their own ambient pieces, most notably Erik Satie and John Cage. It is a well-known fact that the silences in 4’33" were not, after all, silences, since silence is a state which is physically impossible to achieve. Cage had proved to his own satisfaction in 1951 when he went to Harvard University to their anechoic chamber (an environment that is as near silent as technologically possible). Whilst in this space, he still heard two unavoidable sounds – one high, the sound of his own nervous system and the other low, the sound of his blood circulating. Cage therefore proposed that what we have previously described as silence should now be called ‘non-intentional sounds’ – sounds not intended or prescribed by a composer.
Clearly Cage is ‘forcing’ the listener to listen in a very new way. The sound source is now far from obvious. We are listening to the whole, to everything, to the ambience. This ambience has always been there, but whether or not we pay it any attention is another matter.

Early ambient sounds – ‘built-by-man’
• Stone Henge and Burial Chambers
There has been research produced over the past few years into the possibilities of burial chambers and most notably Stone Henge having certain acoustical properties to create distortions in the spatialization of sound (related to standing waves in man made spaces). Whilst it will probably remain unclear regarding how much knowledge Stone Age man knew about the physics of acoustics it could be assumed that ambient sounds, and particularly distortions in ambient sounds, were part of the life of early civilisations and may have had a role in their religious ceremonies.

• Vitruvian Resonating Vessels
The Roman Architect Vitruvius’ understanding of acoustics is extremely impressive for its time. Vitruvius belonged to the Stoic school of philosophy whose followers were aware of the wave analogy for demonstrating acoustical science.
Imagine a stone being thrown into a still pool of water. The impact causes concentric waves to spread across the surface. This analogy demonstrates how sound spreads in all directions. It also demonstrates what happens to a sound when it reaches (or touches) a reflective surface – the sound waves are deflected. Vitruvius’ understanding of this reflection was that it created interference to the original source and in terms of sound made the original less clearly audible or defined.
Vitruvius calls this reflection of sounds resonantia (which differs somewhat from our modern day meaning of the word resonance which implies a sound being bounced back a forth repeatedly at a specific pitch).
The resonantia would have been seen as a considerable problem in Roman and Greek theatres. If strong reflections come back to a listener at slightly different times then speech, for example, will become difficult to understand. As Vitruvius points out, an inflected language such as Latin is difficult to understand when the final syllables of words arrive at slightly different times.
Roman and Greek theatres (which are semicircular as opposed to amphitheatres which are circular) have relatively good acoustics for speech. Anyone who has tried listening to speech in such a theatre is likely to be impressed by the clarity of sound no matter where you sit (there is no real ‘sweet-spot’). These theatres were outdoor venues often built into the side of a hill. The apparent dryness of the resultant acoustic was a problem for Vitruvius when dealing with music and he went to considerable efforts to invent a system that would counteract it. The resonating bronze vessels were to be his solution.

"....... let bronze vessels be made, proportionate to the size of the theatre, and let them be so fashioned that, when touched, they may produce with one another the notes of the fourth, the fifth, and so on up to the double octave.
"....... the voice, uttered from the stage as from a centre, and spreading and striking against the cavities of the different vessels, as it comes in contact with them, will be increased in clearness of sound, and will wake an harmonious note in unison with itself."
Vitruvius - The Ten Books on Architecture in translation by Morris Hicky Morgon

Vitruvius demonstrates how the vessels should be spatially arranged around a theatre, how many vessels should be used and their exact tunings. He follows Aristoxenos’ tunings and shows a considerable knowledge of music theory. It is likely that such tunings would have been used in order to assist instrumentalists and particularly singers with their own tuning. The vessels might be considered as an early artificial reverberation unit, with specific frequencies enhanced and others excluded (obviously ‘real’ reverberation does not function in such a way).
How well might these vessels have worked? In remains unclear, as no examples have ever been found. As has been stated, the musical theory is quite solid for its time. Personally, I find the concept of greater interest than the practicalities…

For more information: -
The Ten Books on Architecture – Vitruvius (Dover)
Music in Ancient Greece and Rome – John G. Landels (Routledge)
Assisted Resonance in Ancient Theatres – Greece and Rome XIV, John G. Landels


How has the Vitruvian concept influenced my work?
In 1996/97 I became interested in the concept of creating an acoustical space that could evolve (that was not static and dependent upon physical constraints). The first 'showing' of this took place at The Royal Festival Hall in February 1998 as an installation in collaboration with Jason Cornish. The sound consisted of quadraphonic pre-recorded CD's and live signal processing of environmental sounds picked up by directional microphones around the site. The result being an acoustic that felt as if it changed without any physical visual change.
Around this time, I was invited to compose a sound track for a CD Rom for Illuminations Interactive (The British Museum, Channel 4 Learning). The project was based upon journeys through Roman Britain and the Roman Empire. The sound track uses similar ideas to the above in that it makes use of exaggerated spatial effects to create changes of feel and atmosphere.
My research into the Romans project and also long term continuing work with Jason Cornish led me to discover the Roman architect Vitruvius and his use of resonating vessels in Roman Theatres.
So, in the 1990's I was creating acoustic spaces with signal processors, tapes and microphones. To my astonishment, it would appear that two thousand years ago Vitruvius was doing a very similar thing with spatially arranged bronze vessels in Roman theatres!
In 1998, I received a Combined Arts Research and Development Award from the Arts Council of England to look into the possibilities of creating a digital model of the Vitruvian vessels as well as continuing my research into ‘evolving acoustic spaces’.

A little more about the digital reconstruction
As can be deduced from the writings of Vitruvius, the vessels themselves respond by ringing sympathetically to external sound stimuli (in a similar way to how the strings of a piano ‘sound’ when the sustain pedal is held down and another sound is projected into the piano’s open strings).
Vitruvius specifies the exact tunings of his vessels and gives alternatives depending upon the size of the theatre they are to be placed in.
In order to demonstrate what the Vitruvian vessels may have sounded like, I initially wrote a programme in Max/MSP that would give the impression of the vessels ringing but without the need for an external sound stimuli (i.e. using the analogy of the piano strings ringing again – the strings ring without any kind of trigger).
I made a number of assumptions about the nature of the sound of the vessels. The closest physical object I could imagine to the Vitruvian vessels was something similar to a Tibetan Singing Bowl or an enormous cut glass wine glass (although it is likely that the Vitruvian vessels would have been much larger). Sounds emitting from such objects are principally sinusoidal and have a relatively long decay.
In the digital domain, creating such sounds is a simple process. I assigned a sine wave to each tuned vessel and decided to listen to the resultant sound by randomly triggering the sine waves so that they formed a constantly evolving drone. My triggers were entirely numerical and were not dependant upon external sounds.
The patch below shows an early example of the Vitruvian Drones Generator. This one has sixteen oscillators, all tuned to a different pitch. It is possible to tune them to those pitches as specified by Vitruvius or to any others. The preset shown below produces a drone based upon the naturally occurring harmonic series. This additive synthesis patch has formed the basis for much of my work over the past two years.



[for high resolution picture click image]

My electro-acoustic work ‘eye speak’ uses a similar programme to create ambient drones but uses the sound of people talking to trigger the drones (the voices are ‘analysed’ by Miller Puckette’s MSP bonk~ and fiddle~ objects). The drones respond to the timbral qualities of the voices as MSP’s bonk~ and fiddle~ objects detect frequency and percussive attack of the vocalisation.
My interest in the Vitruvian concept was born partly from the combination of science and the arts that was prevalent in Greek and Roman times but also from a psychoacoustic stance. Clearly, the Vitruvian vessels are dependant on external sound stimuli to be heard. Vitruvius states that the vessels are to be ‘touched’, presumably meaning that sound waves from a sound source (a musical instrument for example) will radiate outwards and ‘hit’ the vessels making them ring sympathetically.
As a model for reverberation, there are obvious problems – the concept behind reverberation and resonance being quite difference. However, it is also true that a reverberation cannot be heard without a sound source being present. As much of my work has involved attempts at abstracting acoustic spaces from its sound source it became clear to me that with the aid of digital technology it would be possible to abstract the ringing vessels from any sound source by simply triggering there sound mathematically. It would be possible to hear a Vitruvian resonance without the influence of any other sound.


What’s next?
The harpsichordist Vivienne Spiteri and I intend to produce an installation work with solo Harpsichord that takes the Vitruvian concept as a model for creating resonant spaces within a multi room environment.
Imagine; moving through the multi-room environment, each room implying a different Vitruvian resonator (and having its own fundamental resonating frequency), where the harpsichord's overall resonance, as well as selected and isolated overtones from its rich spectra are guided and composed into a work of music through the various and particular acoustic spaces of this edifice.
The installation will be presented as both a live solo harpsichord performance and as a digital audio work using material captured during the live performance. In effect, the rooms will continue to resonate with the harpsichord's material long after the solo performances have been completed – almost like a continuous echo from the past that grows and evolves out of and returns again to, the silence which is the essence of the time-life of the harpsichord spectra.
It is likely that the harpsichords spectrum will be analysed in some way and then act as a trigger for the vessels. However, it is also my wish that the sine waves can be modified so that they can take on the characteristic of the harpsichords own sound (by using a sample of the live instrument and using it as a waveshaper).

Baudouin Oosterlynck from "variations du silence"
sonata for two instruments of silence:
the left ear captures sounds of the inhabited slopes whilst the right ear captures silence of uninhabited regions.....


Selected Works
The following is a list of works that have been performed/installed over the past two years. All pieces have included some form of digital enhancement to an existing ambient space, principally following the Vitruvian idea of creating tuned resonant spaces.
Nova Sound System - an installation for the opening of the new @Bristol Car Park, Bristol March 2000
Eye Propose (York Early Music Foundation Commission) - The QuintEssential Sackbut and Cornett Ensemble, National Centre for Early Music, York 9th April 2000
Cycle Sound System - an installation for 15 Mile Festival (Sustrains, Cycle West), Staple Hill Tunnel, Bristol 24th June 2000
Installation (Untitled) - a collaboration with Jason Cornish (Architect) and Phil Power (designer), Art Haven, Exeter 7th Sept to 5th Oct 2000
eye speak (audio CDR) - Woodstockhausen 2000, 'a tiny festival of esoteric music', Santa Cruz Hills, Santa Cruz, CA, U.S.A., 16th Sept 2000
Audio Installation - Empty Space (Independent Artist Network, Bristol), Templar House, Bristol 20th Oct to 22nd Oct 2000
Audio Installation (Year of the Artist award and DA2 commission) - Prema Arts Centre, Uley, Glos 29th Oct to 9th Dec, 2000
Audio Installation (Lighthouse Commission) - The Lighthouse, Wolverhampton, 23rd Oct to 20th Dec, 2000
eye speak (audio CDR) - En Red O 2000-Electric Songs., Centre de Cultura Contemporània de Barcelona, Mirador Spain 11th to 13th December 2000
Vitruvian Drone and B63 Harmonic Drone - Virtual Concert Hall KAJX, Aspen, Roaring Fork Public Radio, USA 30th December 2000
Vitruvian Drone - Inner Space - a weekly radio program for sound art and droning / drifting soundscapes. 100,5 FM Radio Student, Zagreb, Croatia. 4th February 2001
Vitruvian Drone - The sonic stratosphere, KSER 90.7 FM, Seattle, U.S.A. March 14, 2001
Four Drones - On the Level, Art Shape, Double Reynolds Warehouse, Gloucester Docks, Gloucester 23rd May to 6th June 2001
...so where did it all go? - A Public Auction of Private Art Works (Nina Pope), Kimbolton School 17th to 24th June, 2001

Audio Installation (Year of the Artist award and DA2 commission) - Music without Walls Conference, de Montfort University, Leicester, 21st to 23rd June 2001
Audio Installation (Year of the Artist award and DA2 commission) - The Folk Museum, Gloucester (EyePoppers) 14th July to 11th Aug 2001
Take me to the Magic Square (with a poem by Alyson Hallett), Bristol Community Festival, Hengrove Park, Bristol, 15th July 2001
Crossing Borders (Lighthouse Commission) - The Lighthouse, Wolverhampton, 27th July to 4th Sept 2001
Hymn (10 days lost forever) for Eb Clarinet and Pre-recorded Audio - Kate Romano, University College Chichester, 6th Dec. 2001

I am indebted to the following for assistance with this project: -
Dr. John G. Landells, Sam Moorhead (The British Museum), Marcus Beale (MBA Architects Ltd), Julie and Jason Cornish, The Arts Council of England, DA2 (the Digital Arts Development Agency) and especially Matt Rogalsky – who first demonstrated his own digital drones to me some time ago.

Rob Godman
is a composer working extensively with digital technology. Much of his music explores the relationship between sound and the other senses - can you 'see' a sound or 'hear' visually?
His current acoustic and digital work explores the musicality of ‘everyday’ speech. Last year he was awarded a Year of the Artist Residency (Prema Arts Centre and DA2 - the digital arts development agency). The installations explored how we regard scale, perspective and proportion and how we perceive our surroundings. By using sounds specific to particular regions of Gloucestershire it outlined a location, allowing the listener to travel through it, controlling their own acoustic spaces.
Rob has received performances from artists such as the Siobhan Davies Dance Company, The BBC Singers, Evelyn Glennie, Gemini and the early music ensemble QuintEssential. He had works performed in the UK, USA, Croatia and Spain last year
Future projects include a collaboration with Vivienne Spiteri to produce an installation work with solo Harpsichord that takes the Vitruvian concept of the resonating bronze vessels in Roman Theatres as a model for creating resonant spaces within a multi room environment (Vancouver Island, August 2002).
Rob is Associate Lecturer in Music Composition at Coventry University and also a Lecturer in Programming at the University of Hertfordshire.

For further information please contact:

Rob Godman
4 Mill Close Wotton-under-Edge
Gloucestershire GL12 7LP
United Kingdom
T. (44) 01453 521895
F. (44) 01453 844447
rob.godman@virgin.net
WWW SITES WITH MUSICAL AND VISUAL EXAMPLES

http://www.yota.org.uk/residencies
http://www.ian-workplace.co.uk
http://www.htvwest.com/yota/prog01.shtml

© Rob Godman January 2002