It is the author's aim to explore the ways in which the composer William Wallace (1860-1940), 'served his day and generation by multifarious activities' (Orsmond Anderton, 'A Protean Spirit’, Musical Opinion 1920) and to demonstrate how those activities related to his musical work. As a musician, he was not solely composer but also critic, conductor, musicologist, historian, biographer, campaigner, translator, and innovator in British music at the turn of the century. These are among the issues to be discussed, primarily with a view to their influence on Wallace’s composition, within the course of this document. Distinguishing between Wallace's activities is not an easy task. Many links and overlaps exist between diverse accomplishments and, in allowing different interests to influence each other, he created difficulties in determining the headings under which to categorise his work. For example, an interest in Wagner was to enrich the literary arts of biography and critical review as well as to enhance Wallace's own musical style. For ease, the categories into which Wallace’s work has finally been divided here are the Visual arts. Literary arts. Performing arts and Campaigns for the promotion of British music. The contents of the supplementary Appendix n consist of a catalogue of Wallace’s works, both musical and literary. Again, his musical works conform to four main categories namely Orchestral, Vocal, Theatrical and Chamber Music, while his Literary Works are subdivided into books, articles, academic papers or lectures, published letters and translations. Although not claiming to be definitive, this catalogue is the most comprehensive known guide to Wallace’s works so far compiled and, to the author's knowledge, no previous detailed research into Wallace's work in general has been carried out since his death. This circumstance is here remedied through the collation of information essentially from primary material.