This thesis presents a body of theoretical research, combined with a portfolio of artworks, residing within the field of network music. Network music is a musical practice in which conceptual, technological, ideological and/or philosophical concepts of the network are included in the design, composition, production, and/or performance process. The thesis contains analysis of three historical examples of network music, as well as critical reflection of three artistic responses that have been created by the author. The responses investigate how contemporary technologies allow increasingly complex perceptual and technological understandings of network concepts, ideologies, strategies, and topologies to be explored within network music. The thesis also contains description, critical reflection, and analysis of one original artwork, which investigates a theme that emerged during the research process. The original work explores how a performance topology, adapted from the field of machine learning, alters the perception and interpretation of the network for involved agents, as well as analysing the impact it has on the participants, and performance process. The works included with this thesis constitute the portfolio and they are the creation of the author.

The beauty of sonic waste is a practice-as-research project that contributes to new knowledge through the development of a sonic waste methodology and experiential insights within new compositions. Sonic waste is an alignment of a range of previously unconnected disciplines that collectively incorporate noise, junk objects and extraneous, sounds. The line of enquiry develops an empowering methodology in transforming waste to beauty, in this line of enquiry this is taken to mean the transformation of sounds and objects generally considered unwanted, to a condition of wanted. A holistic, ecological approach is adopted with themes of environmental awareness informing the methods adopted with the compositions. This complementary writing discusses the conceptual and critical topics informing the practical outcomes, and highlights the insights achieved from this approach within the wider methodology. In particular, the disciplines of Acoustic Ecology and Media Archaeology are aligned with the practice. The line of enquiry followed in this study revealed that the engagement within these related fields provided fertile strategic approaches in the development of the compositions. Throughout the critical writing it is argued that this proposed organisation and compositional appropriation of the ever-increasing sonic waste in society produces a positive and pro-active approach to both the understanding and abatement of junk sounds and objects. Through the implementation of this methodology it is possible to engage audiences and contribute to conditions leading towards pro-active change in our understanding of the environmental issues of noise and object pollution. The practice encourages recycling and repurposing waste materials and promotes an awareness of the effects of noise in the environment. The practice portfolio includes a range of outcomes including stereo recordings, live performance, theatre, film soundtracks and sound installations. Four compositions have been selected as case studies, the first two of which are discussed in detail. A wide range of additional studies and compositions were also undertaken to provide focused research insights. These studies fed into the selected compositions and are discussed at appropriate points.

This research project explores Dialogic Coding – a performance practice situated within the field of live computer music which works towards a dialogic relationship with the computer as a programmable musical instrument. The writing articulates a Practice-as-Research (PaR) inquiry that places my practice within specific contextual, analytical and philosophical frameworks. The point of departure is the assumption that following the concept of dialogue a more reflexive way of performing music with a computer becomes possible. This approach may produce innovative results through transformations of musical ideas, embodied interactions as well as the performer's self-concept within a situation of improvised group performance. Dialogic Coding employs the concept of nontriviality to create an independent but at the same time programmable musical agent – the apparatus – which so becomes a co-creator of the improvised music. As a context for Dialogic Coding practice serve other dialogic forms of music making such as free improvised music as well as dynamic performances of programming found in live coding practice. A dialogic approach in music performance is based on listening and the ability to speak one's voice in response to the situation. Here, listening is understood beyond the auditory domain on the level of abstract thinking and physical interaction (interface affordance). This research presents a first-hand account of a computer performance praxis and thus makes a contribution to academic knowledge. For this it makes some implicit or tacit 'knowings' contained in the practice accessible for an outside community through this writing. Dialogic Coding practice was developed through participating in free improvised music 'sessions' with other musicians as well as composing pieces in program code with which I then performed live (solo and group). This writing contextualizes the developed practice in a historic lineage, discusses it within the conceptual framework of dialogism and delineated how a dialogic approach fosters creativity, learning, surprise and flow. As a conclusion I summarise the ethical dimension of Dialogic Coding as a form of human-computer interaction (HCI).

The aim of my research is to investigate, both in theory and in practice, the ways groups work and behave when they are asked to work collectively on the preparation of an open form verbal and/or graphic composition's version. It also investigates the often-neglected topic of who might take decisions regarding the performance of open form pieces for groups, when these decisions are to be made, and the effects on the relationships between performers or between performers and composer. Furthermore, it investigates the potential growth of group creativity and of a group state of mind through collective work between players of open form pieces as well as the problems of working in groups. A theoretical context for the term 'open form' is provided using historical and recent examples from the work of composers of the last and present century, as well as for the terms 'group' and 'group creativity', followed by a discussion of the different manifestations of group creativity and 'group flow' in music and especially in open form musical compositions. These issues are discussed in the context of my own work in composing verbal and graphic open form pieces for groups, which cultivate collective work and responsibility. The commentary explains the way I work as a composer, and the theoretical, musical and social driving force behind my music. It also describes working practices that could present models for other composers to consider when making notated music for groups.

The main focus of my PhD submission is a portfolio of compositions. This selection of pieces presents work for a variety of ensemble types, from symphony orchestra, through different kinds of chamber groups, to compositions for solo instrumentalists. Although all of the pieces were written for some kind of concert setting, my portfolio includes music that was written to act as the basis of a film score, music that uses text specifically written for me to set as part of an operatic project and groups of pieces that share and represent parts of larger connected conceptual worlds. My music explores different approaches to form, content, compositional system, word-setting and instrumentation; however, there are musical and conceptual connections that run across and between pieces, some works realising shared fundamental material whilst others seek to develop in contrasting directions. The portfolio is accompanied by a written component that falls into two main parts. The first part investigates the relationship between narrative and music through a comparative analysis of aspects of narrative theory and music theory. The aim of this investigation was to ascertain whether or not music can be understood to function as narrative and whether such functioning could be described using terminology commonly applied to descriptions of narrative in other artistic media. The results of this investigation revealed a number of possible ways that musical narrative could be understood and described as well as suggesting how such ideas could be applied to the process of composition. The second part of the written component is concerned with a discussion of the works in my portfolio of compositions. Each piece is looked at in detail with regard to all aspects of its context and construction. This approach has allowed for an in-depth examination of my compositional methodology and has facilitated an understanding of how my work and working methods have developed during the course of my PhD studies. For the purposes of this examination, I have divided my portfolio into two broad categories: pieces that engage with extra-musical aspects and pieces that engage with musical conventions of various kinds or, as I have termed them, meta-musical aspects. This division has enabled me to draw out conceptual and musical connections between individual works and groups of pieces; it has also enabled me to suggest ways in which my work operates as narrative. This, in turn, potentially demonstrates that narrative is not something that is necessarily extra-musical but that it might instead be a category that can embrace both musical conventions and a wider conceptual context in the processes of composing and understanding music.

This commentary paper explores two fundamental structural principles of music: repetition and change. In Western art music of the twentieth and twenty-first centuries, there are works that utilise repetition and change not simply as binary tools for musical progression within a piece, but as the actual purpose and character of that work. Similar processes are found in other forms of art, such as visual arts and literature. Each portfolio composition is written whilst pursuing such works of the past, and some of them are reconstructions of similar examples in other artistic media. The introduction in Part One – 1 of this commentary reveals the motivations behind my choice of this particular topic. After examining what composers achieved through repetition, there will be a brief examination of past musical examples containing traits of repetition and change in manners that are intriguing enough for discussion. The analysis in Part One - 2 includes detailed analyses of each work of the portfolio, with explanations on how past examples are applied to my compositions. This section also illustrates how elements of repetition and change found in visual art and literature are musically reconstructed. The conclusion in Part One - 3 describes the transformation of my compositional perspective that occurred during my research. The main issues that were raised when the individual pieces were composed are also discussed.

The aim of my research for the PhD has been to explore the possibilities of sacred music composition beyond liturgical contexts. Although the bedrock of Western sacred music has traditionally been vocal music, I have attempted to broaden the boundaries by delving into the feasibility of instrumental sacred music. The word ‘sacred’ has been used in this thesis in the context of the Christian faith. Chapter I explains the reasons behind choosing sacred music composition as the objective of this thesis. In Chapter II, details of three different approaches are discussed, along with analysis of the individual pieces. These approaches are: application of modern musical language to sacred music; composing sacred instrumental music without pre-existing references; composing sacred instrumental and vocal music with pre-existing references, such as quotations from the established canon of sacred music or derivations of the system for change-ringing English church bells.

This commentary documents the changes in my compositional practice. It explores the rationale for my move towards collaborative compositional approaches, and the variety of processes that I have used. The work occurs in a range of environments, and involves diverse participants, highlighting the relevance of this work for people of all backgrounds, ages and skill levels. By altering the nature of the composition process and its context new arenas for educational and social practices have emerged. This commentary describes some of the benefits and challenges that arise from working in these new ways.

The following commentary introduces six pieces written between 2012 and 2015, during the period of my PhD research at the University of Southampton, UK. All of the pieces discussed here are, on some level, concerned with the subject of borrowing, be it the use of pre-existing musical material, or elements of different traditions, compositional practices in a broad historical context. Different approaches are represented in the ways the individual pieces refer to existing music, ranging from literal quotations to stylistic allusions. The commentary presents the ways these references are transformed, manipulated, and re-contextualised in the pieces discussed. I also attempt to contextualise my music through considering related works by other composers, as well as related debates within postmodern theory. Today - partly as a result of globalisation - the concept of tradition takes on a new aspect: it is less significantly defined by national affiliations, or commitments to particular trends and movements that stem from regional cultures/aesthetics. It is no longer something given, inherited; a multitude of traditions are available to choose from and explore through the arts. In this spirit, the presented works refer to a wide variety of musical traditions, from folk music, through Renaissance polyphony, the German Lied to post-war compositional styles and practices. The commentary includes a general introduction to the compositional techniques lying behind the works presented as well as six analyses supplementing the pieces included in my composition portfolio.

Through the composition of five new works, I attempt to develop compositional methods that might better allow the creation of a more palpable sensation of time within the listeners. I then examine my compositional language, developed incrementally through the composition process for these five works, inspecting the possible implications for understanding a listener's perception and cognition of musical time. Via the repetitions of ideas in my compositions from numerous focal points and depths of focus, I also apply researched ideas, to further examine the complex interrelations between a listener's memory, attention, expectations, and the resultant information levels and hierarchical structures that they perceive. In addition to this, I investigate the role of perceptual pivot points in one's categorical understanding of musical processes. My goal is to address these issues in a way that should advance a better temporal communication with an audience.