This dissertation analyzes the impact of musical transatlanticism on the identities of American communities. I do so through case studies in three time periods: seventeenth-century colonial Massachusetts, the post-Revolutionary Early American Republic, and early twentieth-century Progressive era Chicago. I develop an Atlantic musicology approach that which moves beyond national and nationalist frameworks and traces the strong and lasting musical connections between America and Europe. I explore three kinds of musical transatlanticism: the migration of musicians, the transmission of musical works, and the circulation of ideas about music. Music that crossed the Atlantic Ocean underwent changes wrought by transcription, translation, and contrafacting, and I argue that these changes were instrumental to the self-fashioning of American identity. Intercultural encounter and ideas of difference also drove communities to delineate their conceptual boundaries, although not without ambivalence. Ever in a state of flux, music reflected groups’ self-conceptions both locally and for transatlantic audiences in an ongoing process of conscious and unconscious musical adaptation. A wide-ranging project such as this demands a myriad of historical sources, which range from printed musical volumes to newspapers to diaries and letters. These variegated materials call for an interdisciplinary approach, and I draw on analytic methods from musicology, archival methods from history, and interpretive lenses from ethnomusicology and Atlantic history. I begin with an introduction that elucidates the conceptual and historiographical stakes of the project. The first two case studies focus on puritan psalmody in the seventeenth century. Chapter 1 analyzes puritan ideas about the affective power of music to promote personal piety, and Chapter 2 examines the role of music in colonial encounters with the native population of southern New England. Moving to the late eighteenth century, Chapter 3 traces the circulation of political song, particularly partisan and patriotic American contrafacta of British tunes, through the public print sphere. Chapter 4 turns to the domestic sphere, using one woman’s musical activities as a guide through the contemporary debates over feminine musical accomplishment. Chapter 5 enters Progressive-era Chicago, where European immigrants brought Old World folk repertories to the aesthetically and civically idealistic programs at the Hull-House Settlement. / Music