From the very beginning, George Gershwin's Rhapsody in Blue has existed as an arrangement, yet no one has considered the work in that light. Following the case-study model, I explore a set of arrangements prepared and performed by a suite of musicians who used the Rhapsody in the negotiation of their musical identity: Ferde Grofé, Leonard Bernstein, Duke Ellington, and Larry Adler. Shifting the emphasis away from a centralized text and from the sole agency of the composer reveals a host of new narratives. When cast together these narratives reshape our understanding of the Rhapsody, Gershwin, and music in America. This dissertation expands on current approaches to the study of arrangements and challenges existing and entrenched definitions of "composer" and "composition." In the process of remapping the terrain of this iconic piece of American music, I shed new light on familiar and little-known musicians. Examining a broader vision of the Rhapsody presents possible future directions for Americanist studies in music as we enter a new generation of scholarship in the field—a field that by the early twenty-first century has a substantive body of musicological scholarship on which to stand. At the same time, this dissertation prompts a reassessment of that scholarship, particularly with respect to Gershwin's life and music.