▼ This thesis focuses on twenty-three songs written by the musical theater composer Stephen Sondheim over the fifty-year span of his compositional career. The purpose of this study is to show how these songs qualify as crossover song literature appropriate for the classical voice studio. I shall address this premise through comparison of the crossover performance and the art song to the songs of Stephen Sondheim. Chapter One contains introductory material. Chapter Two is a study on crossover performance. Chapter Three is a general comparison of art song traits to traits of the songs of Stephen Sondheim. Chapter Four provides practical performance details. As source material for crossover song literature, Chapter Five surveys ten shows and twenty-three songs of Sondheim. An introduction to each song begins with a list of source(s) and details, such as range, tessitura, and Fach. Analysis shows each song’s compatibility with basic-to-advanced vocal protocol. An integral part of my analysis focuses on individual motifs and detailed graphs—with suggested phrasings – emphasizing Sondheim’s extensive and precise motivic organization. Several of the earlier songs do not rely heavily on similar organization, so only the basic form is analyzed. Chapter Six summarizes the qualities that make Sondheim’s twenty-three songs appropriate for the academic, classical voice studio and ultimately challenges voice teachers to familiarize themselves with crossover literature. These musical theater songs can be sung well in a classical voice studio without compromise or harm to vocal technique. Granted, they may not sound like Broadway when sung with a legitimate technique, but they will prove advantageous for teacher and student alike. Containing intricate and sophisticated modern language, subject matter, and motivic organization, these songs by Stephen Sondheim provide a necessary link between the contemporary student and the school of music. Advisors/Committee Members: Pendle, Karin.