Drawing on extensive archival work, this book examines the crucial contribution of Neapolitan string virtuosi to the dissemination of instrumental music and to the development of string practices and musical culture in Europe. It presents a fresh look at the central place of instrumental music in early modern Naples and considers aspects of music pedagogy, performance practices, patronage, and musicians' social mobility. Music examples, paintings, and lists of personnel of major music institutions inform the discussion and illustrate the opportunities for social mobility afforded by the music profession. Music production and consumption are considered within their cultural, political, and economic contexts and in connection with the rapid political changes of eighteenth-century Naples. This substantial contribution to the understanding of a previously under-studied repertory places the cultivation of Neapolitan instrumental music at the centre of aesthetic and cultural developments across eighteenth-century Europe.