RNCM: Simon Knighton – ‘Sound Sculpture No.1’

simon knighton head shot

Simon Knighton

[This is part of a series of blog posts by project participants on their work. Simon is a PhD student at the RNCM]

Sound Sculpture No.1 was performed at the RNCM on the 14th February 2020. A project summary (including recordings) can be viewed here: https://www.simonknighton.com/concert-piece/sound-sculpture-no1-2020


Capturing Indeterminacy to Explore the Spectral Potential of the Clarinet

Sound Sculpture No.1 is a piece for five clarinets, eight loudspeakers and sixteen electronic soundscapes which uses technology to exploit the timbral range of the clarinet and explore how the perceptual qualities of sonic spectra can be used to source-bond[1] electronically produced sound to acoustic instrumentation.

The piece was composed as a response to some of the questions asked within The Garden of Forking Paths research project, through which I was introduced to ideas of instability and indeterminacy in clarinet playing technique and sound production. It became clear how much flexibility the clarinet has in producing an almost full range of simple to complex spectra.[2]  This makes it an ideal instrument with which to explore the perceptual qualities of sonic spectra with the aim of source-bonding electronic sounds to acoustic instruments. However, some of the more esoteric inharmonic sounds that the clarinet is capable of producing are products of momentary instability which arise in entirely contextual and difficult to control circumstances.

The Garden of Forking Paths project aims to find solutions to some of the compositional and performance issues which arise when working with indeterminate instrumental sound production/playing techniques. My contribution to this line of thinking is to use audio sampling and time stretching to ‘capture’ these unpredictable and indeterminate sounds so that they can be used with equal precedence alongside the more easily accessible and reproducible ‘ordinary’ clarinet sounds which are more commonly associated with the instrument. Within Sound Sculpture No.1, this greater degree of control is used to create sixteen steadily evolving soundscapes which traverse the sine wave to noise continuum, whilst presenting the qualities of the clarinet in fine, microscopic detail. The entire piece is bookended by a synthesised sine wave at the beginning and white noise at the end; this highlights the extremes of the continuum (all other sounds are processed clarinet samples). Starting from a primarily acoustic sounding starting point, the piece also attempts to gradually ‘reveal’ a more electronic sound pallet as it moves towards inharmonicity.


layout of loudspeakers

fig.1: layout

Movement One <video>

The first movement of Sound Sculpture No.1 is an acousmatic surround sound installation which explores sonic perception by inviting audience members to move around a space and listen at varying distances to multiple speakers which each project separate tones derived from the harmonic series. All sounds are electronically treated clarinet samples. This explores how individual tones create the whole.

Movement one was inspired by this kind of Max patch:

Movement Two <video>

[Please remember that the spatialisation effects which were present in the performance are not audible in the stereo recording.]

The second movement aims to confuse the senses by establishing ambiguity between acoustic and electronic sources: parameters can then be controlled in unexpected musical ways, as sounds believed to be from an acoustic source are treated electronically (and vice versa). Live performers (positioned around the edges of the space, with audience members in the middle) play tones, sounds and extended techniques which are mixed with pre-recorded clarinet samples and synthesised tones. These sounds are panned around the room to create spatial motion effects; this creates the illusion of connected, singular tones which begin with a clarinet on one side of the room, and then appear to seamlessly move across the audience before joining with an adjacent clarinet. For this illusion to be successful, the live instruments must blend with the electronics with absolute homogeneity; this establishes the need to develop composition methods which integrate an understanding of the phenomena relating to acoustic/psychoacoustic theory which lead to perceptual homogenisation. Indeed, spatialisation is used to provide a richer sonic canvas on which to explore and utilise such phenomena.

sound movement diagram

Figure 2 – Sound Movement Diagram



The form of the second movement of Sound Sculpture No.1 follows a trajectory from sine waves, to harmonicity, to inharmonicity; to white noise through sixteen evolving soundscapes. The first eight soundscapes are comprised of pitch choices that have increasing tension, dissonance and harmonic complexity. The form is designed so that each section becomes increasingly spectrally dense (trough the number of notes and the spectral complexity of the sounds used) and increasingly deep (the pitch range floor gets gradually lower). Soundscapes 9-16, on the other hand, are freer and more exploratory: these sections are less interested in keeping the relationship between acoustic and electronic sound homogenised with a largely acoustic sound-world and are more in favour of creative experimentation around composing with acoustic and psychoacoustic principles in order to explore the creative possibilities of this unique set up.

sound spectrums

Figure 3 – Spectral Summary of form across 16 soundscapes.


Examples of Spectral Exploration Along the Sine Wave to Noise Continuum

With the greater degree of control that the technology afforded, it became possible to use the clarinet to explore sonic spectra in a variety of interesting ways. Here are some descriptions of the acoustic and psychoacoustic phenomena that were explored within selected sections of the piece.

[Click the titles for YouTube-timestamped links to the correct place in the video]

Soundscape 1 – Sine Waves

An electronic sine wave starts the piece and is accompanied by the front clarinet, who plays a harmonic note a minor 3rd lower. A recorded version of this clarinet harmonic then enters and pans across the room, joining with the centre and back clarinets. The perceptual qualities of sine waves[3] and instrument harmonics creates a spatially ambiguous, rather directionless sound which creates a sense of fusion between acoustic and electronic sound. The interaction of unison pitches also creates beating[4] patterns between acoustic and electronic sound (adding another ‘layer’ of interaction).

Soundscape 4 – Harmonicity

The effects of harmonicity are used throughout to perceptually connect the live clarinets with the electronic parts. The pitches of the sampled clarinet start off in unison and then become increasingly less related to the fundamental as the soundscape moves across the room, thus providing a tight fusion from acoustic to electronic sound.

Soundscape 9 – Ordinary Tones

Soundscape 9 starts to integrate a deeper electronically produced spectral range, far outside the capabilities of an acoustic clarinet quintet. Lack of onset synchronicity[5] is used to create an acute awareness of the clarinet locations within the room by staggering the accented clarinet entrance points

Soundscape 10/11 – Gestalt Laws of Good Continuation

In soundscapes 10 and 11, ordinary tones (which are a form of complex waveform and will be much more easily localised by the listener in comparison to harmonics) are used with rapid staccato[6] playing technique. The electronic parts recognise this heightened perception of sonic localisation by having samples of the staccato parts move very obviously across the surround sound field: the use of electronics and the sense of illusion and the uncanny is highly evident by this point.

Soundscape 14 – Bell-like Inharmonicity

Soundscape 14 consists of only multiphonics tones with an electronic part comprised entirely of multiphonics samples. This creates a complex, non-harmonic soundscape with spikey, angular, dissonant harmony. Many streams of sound should be heard in the space, rather than homogenised mass of earlier, more harmonic soundscapes.

Soundscape 15 – White Noise-like Inharmonicity

By soundscape 15, the piece has transformed entirely into inharmonic spectra, in the form of breath noise, rattles etc. Notice this only uses acoustically produced inharmonic spectra, hence the lack of low-end bass information and the overall low amplitude of the soundscape.

Soundscape 16 – Coda

The final soundscape acts as a kind of coda which summarises the whole piece through means of morphing from harmonicity to inharmonicity, whilst simultaneously morphing from entirely acoustic to entirely electronic. The piece employs combination tones[7] and the missing fundamental effect (by asking the performer to play an ordinary note whilst simultaneously humming a perfect fifth higher) to blend acoustic, electronic and psychoacoustic sound.


Next Steps

The whole process of creating this piece—from working closely with the performers in order to record the fine details of the instrument, to studying the fundamentals of acoustics and psychoacoustics with the intention of applying the theory creatively—was extremely enjoyable, informative and illuminating. This kind of music making requires a very collaborative approach with the performers. Fortunately, I have found that these ideas tend to attract performers who are excellent to work with; perhaps because they have interest in developing these kinds of ideas within their own practice too, it tends to open very interesting collaborative doors. I hope to continue to design a collaborative methodology that utilises the knowledge and experience of the performers (and helps them to learn and develop their own relationship with their instrument), whilst also developing my own research and composition practice.

I now aim to create a series of Sound Sculptures: one for each instrument family and a final one for symphony orchestra. Through creating this series of pieces, I will continue to develop my methods of capturing indeterminacy and exploring instrumentation, from which I hope to develop a musical vocabulary which ultimately presents the instruments of the orchestra in new and interesting ways.



Deutsch, D. (2013). The Psychology of Music (3rd Edition). Elsevier.

Smalley, D. (1997). Spectromorphology: Explaining sound-shapes. Organised Sound, 2(2), 107-126. doi:10.1017/S1355771897009059


[1] Source bonding is “the natural tendency to relate sounds to supposed sources and causes, and to relate sounds to each other because they appear to have shared or associated origins” (Smalley, 2014).

[2] Waveforms can be either a simple tone or a complex tone. Simple tones (also known as sine waves, pure tones etc) consist of only a fundamental frequency. Complex soundwaves are formed from two or more simple tones, the lowest of which is known as the fundamental; anything above the fundamental is known as a partial or overtone. It is the relative amplitudes of the partials that give a sound its timbre. Evenly spaced overtones above a fundamental frequency give a tone a ‘pitched’ quality. The components of a waveforms will perceptually fuse if “their frequencies are integer or near integer multiples of the fundamental frequency” (Deutsch, 2013, p. 185): this is known as “harmonicity”. Overtones which are not integer multiples of the fundamental create inharmonicity. Bells are an example of inharmonic waveforms, and electronically produced white noise is an extreme example of an inharmonic waveform (where all frequencies are present equally). Simple and complex waveforms have distinct features which when cognitively processed have different perceptual qualities.

[3] Humans can’t perceive the location and directionality of sine waves with as much ease as complex waveforms. According to Platz and Wharton, It is merely a convention to conceive of an instrumental sound source as a point in space. Actually, different timbres can suggest different spatial positions. The reflections from various directions give a sound its spatial qualitiescertain fingerings on the clarinet enable a player, at low volumes, to produce a note almost free of overtones, and these, being the nearest possible [acoustical] approximation of a sine wave, are perceived as directionless” (1995, p. 23-28).

[4] Beats are an acoustic (not psychoacoustic) phenomenon that occur when two sounds of slightly different frequencies create tremolo like modulations in amplitude.

[5] Onset/offset synchronicity is an important factor in determining the closeness of perceptual grouping between harmonics and partials. In nature, a sound complex of partials will always sound simultaneously, therefore, if tones of the harmonic series are introduced at different times, they will more likely be heard as separate tones (Deutsch, 2013, p. 187).

[6] The psychological Gestalt law of good continuation (Deutsch, 2013, p.184) suggests that the staccato playing techniques used will still create a sense of coherence between acoustically and electronically produced musical gestures.

[7] Combination tones (also known as sum and difference tones) are a kind of auditory illusion that is created when the sum or difference of two tones creates a third ‘ghost’ tone. The source of this ghost tone is the result of “non-linearities in the audio system producing the sounds or non-linearities in the hearing mechanism” (Greated, 2001). A similar psychoacoustic phenomenon is known as the ‘missing fundamental’, whereby if the first two overtones of a harmonic series are presented the brain will create a tone an octave lower than the first overtone to ‘fill in’ where it expects the fundamental to be. Whereas combination tones are a physical effect, missing fundamentals exist entirely in the brain and are more prominent when the tones used are rich in harmonics (Horvát, 2017).