sdf PhD





Exploring visual representation of sound
in computer music software through
programming and composition



Selected content from
a thesis submitted with a portfolio of works to the University of Huddersfield in partial fulfilment of the requirements for the degree of Doctor of Philosophy

December 2013

Samuel David Freeman

Minor amendments
April–June 2014

1: Introduction

Sound is a fleeting and transitory phenomenon; existent as itself only in the moment. […] In the composition of music it is representations of sound that are worked with, whether that be the dots and lines of common music notation, a sound-recording medium, or computer software. […] This project began by asking:

1.1 Motivation

The motivation for these lines of questioning came, in part, from the experience of having elements of my compositional practice examined in research by Jean-Baptiste Thiebaut on the use of sketching by contemporary composers (Healey and Thiebaut, 2007; Thiebaut, 2010). Thiebaut's case study featured a series of my compositional sketches from my 2006 eight-channel work Octorgan, and include some early development of what I now refer to as spiroid-frequency-space representations of the frequency-domain. Observation of the spiral structure emergent from several octaves of a scale of notes arranged in a circle, however, for me began in the compositional process of an earlier piece, six notes of a whistle flute (2005). Pen and pencil on paper have always featured extensively in my musicking, but it was with those two works that a consciously meditative approach to geometrical drawing in the exploration of musical ideas took seed.

In realising musical ideas which are borne through the free association of geometrical forms with conceptual facets of sound, the challenge was encountered that available software did not share the same associative values. Ideas had to be re-thought, and thus re-shaped, in order to manifest as sound through the technology at hand. This project thus set out to close the gap between ways of thinking derived from intuitive spatio-visual exploration of ideas to the ways of working permitted by existent software. […]

The motivation to develop a bespoke software environment in which to compose new music began as a move away from the live laptop performance based work that – alongside computer music pedagogy – had been my focus in the years prior to the start of this project. As a continuation of my earlier compositional practice, this project was initially proposed to explore methods of visual representation specifically designed as circular in appearance. During the progression of the research, in light of new findings and changing perceptions of the work and its context, the scope of this project has been refined, and its aims and priorities have been adapted.

1.2 Initial context

1.2.1 Representations of sound

It is easy to think of there being sound inside the computer when we work with it, but really we know that there are only representations of sound – either as recordings or synthetic potential – from which actual acoustic sound can then be produced via transducers attached to outputs of the computer system. Sound recordings exist within the computer as audio-buffers and sound-files in the symbolic form of time-ordered numeric values, but it is possible to think of this simply as being 'digital audio' in the same way that we may think of there being 'analogue audio' on lengths of tape without giving much thought to the physics of magnetic fields and so on. Likewise, the programmatic algorithms describing the synthesis or processing of digital audio in software can be thought of as equivalent to the electronic phenomena in analogue circuitry – whether that is what the software is modelling or not.

Although not limited to do so, software often mimics the audio tape medium, albeit in greatly augmented ways. By accepting digital audio as an extension or continuation of the technological ability to record and reproduce sound, we also accept the ways of thinking about, and working with, sound that the previous technologies provided. Applicable to digital audio are thus, for example, the techniques associated with the musique concrète and acousmatic traditions.

The invention of musique concrète was possible in the mid-twentieth century because of a practice which took root in the mid-nineteenth century: the art of recording sound as a trace of its vibrational motion. In contrast to music that is made by working with recorded sound, we can look at a form of symbolic representation which has a much longer history in the theory and practice of music: the scored notation of sound parameters. Towards the matter of musical notation, and opening with a statement of aesthetic pertinence, Gareth Loy (2006, pp. 11–12) writes:

The realm of personal musical experience lies entirely within each one of us, and we cannot share our inner experiences directly with anyone. However, many world cultures have developed systems for communicating musical experience by representing it in symbolic written and verbal forms. […] one such system [is] the Western common music notation system (CMN). Its prevalence today makes it a good entry point to a broader discussion

Conversational description of this project, and the research context from which it stems, has often called upon the concept of 'dots on lines' (in reference to common music notation) as a starting point because this is a familiar form of visual representation in music. The idea that the act of arranging dot-like symbols on horizontal lines can be described as 'composing music' is generally accepted because it is well enough known that such symbolic representations can be interpreted to produce a prescribed sequence of sounding events. […]

Several centuries of CMN use and development have nurtured an approach to music 'which starts from an abstract conception and notation leading to a concrete performance', and it was 'against the "excess of abstraction of [his] period' that Pierre Schaeffer reacted with the concrète approach to music. Schaeffer 'started from the concrete sound material, from heard sound, and then sought to abstract musical values from it' (Chion, 1983, p. 37).

One way of describing the work undertaken in this project would be to say that it seeks to look into the essence of those representations of sound that may commonly be thought of as being the sounds that they represent. Representations of sound in visual form can only ever portray a metaphorical shadow of the thing being represented; only ever can some of the characteristics of sound be shown because sound is not itself a visual phenomenon. In choosing to employ a particular method of representation for the purpose of organising sound as music, one delimits the realm of potential control and thus determines the scope of interaction within that work.

1.2.2 Computer music software

A significant characteristic of contemporary culture is the omnipresence of software systems (Manovich, 2008). What possible implications this situation may have to new musics are approached by this research, and the resultant difficulties encountered in defining an artistic 'work' as distinct from the 'tools' used to make it are also explored. Computer music software, as referred to in the title of this project, could be taken as to encompass any and all software which may facilitate musicking in its many and varied forms; from digital audio workstation (DAW) applications to digital media players and contemporary web browsers. This project investigates the interactive processes of composition that transpire between a human composer and compositional materials in their manifest state as visual representations in computer music software. Creation of new software systems (programming) is an integral part of my compositional practice. Whereas programming was, in my works prior to this project, thought of as a means to an end in the pursuit of sound making systems, this research has set as its context the conscious engagement with the software medium.

1.3 Thesis structure

The following chapter (§2: Looking at sound) describes the techno-aesthetic1 basis for this practice-based research by examining (first) physical properties of sound, and technologies by which are able to see them, and (second) some of the psychoacoustic aspects of sound upon which portfolio works find context.

Chapter three (§3: In software, on screen) presents six portfolio pieces, each with their own contextualisation; these pieces comprise a developmental trajectory with an increasingly philosophical approach to the methods and materials being worked with. That chapter concludes (§3.7) with a discussion of 'software as substance'.

The spiroid-frequency-space concept, that has already been mentioned (§1.1), is introduced in chapter four (§4: Spiroid). The formalisation of the concept within this project, the wider context of similar structures, and my first software implementations of it are described.

The CirSeq concept is then the subject of chapter five (§5: CirSeq); its inception as a 'time-space' counterpart to the spiroid-frequency-space visual representation is detailed, and the compositional use of a software implementation of the concept is discussed.

Chapter six (§6: sdfsys) describes the work that is a culmination of the preceding works; development of the sdfsys computer music software environment, across its alpha and beta versions are presented. Compositional practice is then explored through new pieces that have been created with sdfsys.

Final conclusions, and proposals for further work are discussed in chapter seven (§7).


← sdf PhD thesis start

2: Looking at sound →