This book is a detailed study of the Canadian pianist, broadcaster, writer, and composer Glenn Gould (1932-82). While focussed primarily on his performances, it also situates his work and thought more broadly within relevant musical, cultural, intellectual, and historical contexts. It incorporates most of the existing primary and secondary literature on Gould, as well as many ideas, interpretations, and perspectives that have never before been offered. It also incorporates ideas from a wide range of literature, both musical and otherwise, and has benefitted from on-site research at The Glenn Gould Papers in the National Library of Canada. The book offers a more comprehensive, balanced, and thoroughly researched portrait of Gould as pianist and interpreter than any previous volume in the Gould literature. Following an introduction that summarizes Gould's career and the posthumous interest in him, the book divides into two parts. Part 1, `Premises', focuses on the intellectual and aesthetic ideas that informed Gould's performances, and draws on literature from many fields, including music history and aesthetics, cultural history, the history of performance practice, theatre, literary criticism, and music analysis. The three large chapters of Part 1 cover a wide range of topics: Gould's idealism, views on the musical work, musical tastes, and repertoire; his position on the role of the performer; the analytical, critical, and ethical discourses embodied in his performances; and his approach to performance in the contexts of Romanticism, modernism, neo-Classicism, post-structuralism, the historical performance movement, twentieth-century theatrical and literary practices, and cultural currents in the 1950s and 1960s. Part 2, `Practices', focuses in detail on Gould the pianist, illuminating important features of his style through prose description and critical analysis, and including graphic musical examples and plates. This second part focusses on specific aspects of Gould's performance practices: his relationship to the piano; his approach to counterpoint, rhythm, dynamics, articulation and phrasing, and ornamentation; and his uses of recording technology as a kind of performance practice. A conclusion serves in part as a summary of previous findings, but also discusses how, in light of these findings, Gould's work as a performer might ultimately be assessed.