In this thesis I present an overview of my approach to free improvisation with particular reference to the clarinet's instrumentality (its intended function) and its materiality (its accidental characteristics). Acknowledging an influence from the clarinet, I set out to discover its role in defining the music I make. After outlining debates surrounding improvisation in terms of its compositional capacity, I then consider free improvisation in terms of relational aesthetics. The remainder of the thesis is divided into three main parts. The first part explores philosophical and practical issues related to tool-use. In chapter one I discuss observations about objects, leading to conceptions of instrumental design. Discussing the special case of artistic tools I suggest an intrinsic link between intent and possibility, considering this relationship in terms of working with an instrument's design and materials. In chapter two I elaborate on ways in which instruments can lead towards musical material while addressing issues of culture, uncertainty and relationships. I describe a veneration of instruments as guides in free improvisation and suggest subverting traditional gestures as a strategy to advance an instrument's capacity. I address issues of uncertainty and posit failure as a viable aesthetic stance, welcoming rethought into performance. Part two sees greater emphasis placed on my own praxis. In chapter three I outline uses of the clarinet with particular focus on its materiality. In chapter four I discuss recent recordings in light of the issues raised in the thesis. This part is accompanied by a DVD (also available online1) containing examples for chapter three and recordings for chapter four. After a conclusion, which provides a summary of findings alongside a discussion of my current praxis, I present part three, a recording of a final performance made on 13/01/16 with Benedict Taylor (viola) and Daniel Thompson (guitar).

This thesis investigates the development of the recorder's microtonal repertoire from 1961 through to 2013. The artistic impulses for the use of microtones are discussed and selected pieces studied and performed. An investigation is also undertaken into the relationship between pitch, dynamic, and tone colour. This leads to the development of a method for objectively identifying the changes in tone colour that result from using various microtonal fingerings. Very little substantial research has been undertaken into the recorder's contemporary repertoire, and even less so with regard to its engagement with microtones. The skills for producing the expressive effects of dynamic and tone colour, and thus microtones, were known in the early 16th century, lost, and then revived during the period of musical experimentation in post-war Europe. The application of this knowledge, however, has remained limited. This thesis addresses these shortcomings. Following consideration of intonation and interpretation in Chapter 2 a survey of writings analyzing changes in tone colour and dynamic, and the relationship between them, is undertaken in Chapter 3. These include a number of foreign language texts, whilst others appear in American journals, or conference papers not generally available to the British reader. They highlight the tendency for writers to discuss tone colour and dynamic in vague and subjective terms, and in relation to the performance of early music but rarely in the context of contemporary music. This strand of my inquiry is brought to fruition in Chapter 5, where research leading to the development of a method for identifying and quantifying changes in tone colour, through the application of different fingerings, is applied for the first time. The results of an investigation into the evolution of microtonal repertoire composed since the 1960s are recorded in Chapter 4. Different compositional approaches to both instrument and microtonality are reflected in my choice of seven pieces, plus my own composition, that are the subject of detailed study in Chapter 6. The analyses of the pieces discussed in this thesis, and the contexts in which they were composed, represent a significant step forward in the understanding of the instrument and the use of microtones in compositions of the period. My thesis concludes with a live performance in which a selection of microtonal pieces is presented. This serves as a demonstration and confirmation of the principles discussed in this thesis, drawing together the threads of my research, and applying the insights gained in the course of this study.