This chapter proposes that the history of musical emotion pivots on a core period of “affective realism,” coterminous with the common practice period and the writings of Descartes, Spinoza, Hume, Smith, Darwin, and William James. In this period of “affective realism,” emotion is objectified, individuated, mimetic of human behavior, and subjective. Prior to 1600, emotion, by contrast, is fluid, relational, transcendent, divine, and the province of theology. The main body of the chapter reviews the seminal work of three historians of emotions: Norbert Elias, Barbara Rosenwein, and William Reddy, together with their concepts of “civilizing,” “emotional community,” and “emotives.” The chapter concludes with a critique of performance theory, focusing on a performance analysis of a Bach violin sonata.