Trevor Wishart
THE EMOTIONAL IMPACT OF SONORITY

(Extract from paper for the “Music and Emotions Conference”, Durham, 2009)

Before I begin I would like to point out some important differences between traditional composing and composing electro-acoustic music. In traditional compositional practice (at least for Western notated musics) a composer deals with the abstracted properties of sound events, such as pitches related to a particular scale system, notatable rhythmic patterns, and specific sonority classes (or instruments). The technology of instrument design is honed to produce consistent sonorities over a range of pitches, and notation allows us to organise these abstracted properties in a logical/emotional schema.

In contrast electro-acoustic music is concerned with sounds in their totality, and any sound whatsoever can be used as starting material. It need not have any definable pitch or any easily categorisable sonority – for example, a complex portamentoing vocal ingressive, or the sound of a particular glass-object being broken. A simple way to understand this distinction is to think about pitch. In the traditional sense we think of the pitch of a sound as a member of a class of pitches (e.g. C or Eb) which we can relate to other pitches (e.g. D or G#) within a scale system. However, a sound can be pitched (example, a vocal glissando) but not be relatable to any scale system or harmonic schema. In spectral terms, however, this is still a pitched sound, as pitch is something that derives from the physical relationship between the partials within the sound, and distinguishes this type of sonority from others that do not have this spectral quality.

It is the power of computers that has allowed us to tease out the inner workings of sounds in all their multidimensional complexity, realising and transcending the aspiration in Schoenberg’s ‘Five Pieces for Orchestra’ to make timbre an accessible parameter of musical thought. We have moved from the situation where timbre is little more than a set of descriptive labels, like ‘chalumeau-register clarinet’ to a precise physical description of the inner architecture of sounds, and we now have the possibility to manipulate and transform sonority itself.

My own concern as a composer has been to expand traditional notions of musical transformation and development into the spectral domain. Hence, just as a traditional composer might transform a melodic motif from the major key to the minor, rotate or invert a tone row, or perform set manipulations on a hexachord, in the spectral domain we can create new instruments which transform the sonority of a sound, changing it in subtle or radical ways, and hence develop sets of musically related materials which can be used for building a musical discourse.

As an aside, I would also add that, even in the world of popular music, much of what gets taken for mere recording of musical events is in fact an electro-acoustic construction manufactured in the studio by a professional producer.

An example from ‘Imago’

My first example is a particular event in my piece Imago, and I will discuss how I understand the emotional impact of this event as it develops and recurs throughout the piece. I want to stress that what is being presented here is a post-hoc analysis of what is going on in the piece, not a description of what I’m thinking when I’m in the process of making it. When composing I listen, select, reject and arrange materials in direct emotional / logical response to what I’m hearing.

Imago is a 25 minute piece developed from a tiny source sound, the clink of 2 whiskey glasses, which lasts about one fifth of a second. It is not important at all that you know or recognise this sound as the clink of whisky glasses. In fact I only discovered that this is what it was some years after making the piece, as the source material is taken from an existing piece by Jonty Harrison. As with traditional musical, what is important is what happens to this material on its musical journey.

The poetic of this piece, as implied by its title, is the emergence of something surprising from an apparently unpromising source (an example of an imago is the butterfly which emerges from the unprepossessing Pupa).

Here is how the piece starts, intentionally low-key, verging on the boring … how can anything musically interesting come of this ?

Sound Example 1
(Opening phrase of Imago)

But soon the transformations of this material begin to take off ..

Sound Example 2
(early phrase of Imago where the source repeats rapidly through to the birdsong-like transition and massing of events)

I would now like to focus on what, at first hearing, would appear the least interesting of these events. Most of the transformations, so far, retain the bright-attack-to-pitched-resonance structure of the original sound. But one of these sounds is more like a washed-out band of noise which crescendos and decrescendos.

Sound example 3
(First part of previous example, centring on the ‘Fugu’ sound)

This is what I call a ‘Fugu’ sound, after the Japanese poisonous-fish delicacy, and it is made by joining together a time-reversed copy of the source, with the source itself. This makes an event which emerges from nothing, crescendos to a peak, and then dies away to nothing again. More importantly, because. in the original sound, we experience the brightest event at its start, in this transformation we here the sound become brighter as it crescendos, and less bright as it fades. This exactly parallels our experience of hearing a sound approach and recede from us in the real world. The brightness, the high frequencies, are heard most clearly when the sound is very close to us. So the event suggests something that emerges out of the mist, appears briefly in front of us, then, just as mysteriously, vanishes again. At this stage in the piece we are hardly aware of any of this, as the bright-attacked sounds around it capture our attention.

For example, a more striking transformation at this stage is the spectral-sequence which takes us to a drum-like sound.

Sound example 4
(Clink ◊ ‘Drum’ transition)

And this sound is established as an anacrusial event in the piece (it signals the arrival of new material, which material may or may not appear – I like to play with this sense of anticipation).

Our Fugu event can be expanded in simple ways, by time-stretching, and /or transposition, for example….

Sound example 5
(Simple transformations of the ‘Fugu’ event)

But in the piece I choose to filter the event, and stack time-stretched filtered copies such that the crescendo in brightness is enhanced by a harmonic stacking of events with higher and higher pitch. The event now has a strong harmonic presence, and this enhances its mysterious quality. Here is an example (at the end of this next sound-example).

Sound example 6
(Appearance of harmonic Fugu event, in context)

Eventually, this event reaches its apotheosis in the piece. Massively time-stretched, and the harmonic stack extended very high, I also make a special transformation at the point of maximum brightness. We are first presented with identical copies of this sound on the two loudspeakers, which means we hear a mono source at the centre. At the peak, I timestretch the peak-material, but slightly differently in each channel – this means that the event suddenly becomes stereo, it suddenly fills the stereo stage at the point of maximum brightness and loudness.

Sound example 7
(Transition to and appearance of ‘Ocean’ section)

Whatever this mysterious event presaged, it has now definitely arrived … it presents itself, metaphorically, as a wave passing over our heads, and this wave-metaphor is counterpointed by the organisation of the other materials. Very briefly these are many, many variations of that simple material which opened the piece, time-stretched, time-contracted, spatialised , spectrally distorted in various ways, and accumulated into a dense mass, which is then filtered and changed in level to suggest real ocean waves – although, all the time, we are aware this is an illusion.

However, this is not the end of the story. As this section winds down, our event dies away into the background, until the very end of the section.

Sound example 8
(Fade away and transition out of ‘Ocean’ section)

At the section end our event, for the first time, shifts in pitch at its peak, and this is a marker of transition – it heralds the start of a new section. The meaning of the event has slightly changed.

Towards the end of the piece, we hear this event reinterpreted one final time. We already know what to expect if we hear that massing texture, and that slowly crescendoing pitch. But at this stage we know the piece is approaching its end. The final big moment of Imago sees the emergence of a grand gamelan-like event, which comes to an end, then the music winds down, suggesting perhaps the running down of some huge mechanisms. Despite this moving-to-a-conclusion marker, we hear the start of the ocean material again, and we think we know what to expect.

Sound example 9
(2nd Gamelan phrase to end of last Fugu event)

However, here our event reaches its peak, makes the pitch shift, indicating we should expect a transition to something new, but then falls back to its original pitch and the whole sonic world rises and dissipates somewhere in the sky. The ‘something new’ turns out to be the dissipation of the material itself. The magnificence is spent, the power exhausted. We should now really expect the end and, in fact, the end of the piece is only a few moments away.