Performance analysis is today the most important and widespread method in Theatre and Performance Studies. Since its invention in the 1980s, it has enabled a systematic study of cultural performances of very different kinds, both inside and outside the realm of theatre, thereby providing answers to a broad range of research questions. This chapter briefly presents the most relevant traditions of performance analysis and then discusses how the method has the potential to be developed further, allowing deeper insight into the affective dimension of performances. Contemporary examples from the field of theatre and migration and from immersive theatre demonstrate how difficult it is to develop a profound analytical tool for understanding the affective power of performance: How can affectivity be described as a performative process? From what perspective can such a description be provided? Is there really something like “a” performance as “the” object of analysis, as Theatre Studies has so long assumed? Reflecting on these questions, we argue for a new way of analyzing performances: one that takes the polyphonic and relational structure of affective experiences fully into account.