This document examines how four late twentieth-century composers' styles engage with the traditional genre of the etude. It explores the stylistic characteristics of concert etudes by John Cage (Etudes Australes), William Bolcom (Twelve New Etudes for Piano), John Corigliano (Etude Fantasy), and György Ligeti (Études pour piano, Premier Livre). The interaction of these composers' styles with the general characteristics of the etude is explored from a performer's perspective through a comparative study of these four collections. The introductory chapter provides a brief historical survey of the etude from the late eighteenth century to the twentieth century. Chapters two through five consider the etudes of Cage, Bolcom, Corigliano, and Ligeti in turn, summarizing their respective styles, examining the interaction of their styles with the virtuosic nature of the etude, and providing helpful instructions for the performance of these works. Chapter six briefly compares and contrasts the etudes of these four composers with each other as well as situates these works within the context of late twentieth-century piano music. This document contributes to our understanding of how the etude genre has been embraced by late twentieth-century composers as well as how they have engaged, to varying degrees, with the nineteenth-century attributes of the genre.