A historian of theatre, the author of this article wants to show how the notion of performance, in its broadest sense, can help enlarge and deepen the analysis of past and present theatrical events by envisioning them as single sessions. This approach will promote a better understanding of heterogeneous events that mirror the heterogeneity of their audience, and take into account the fact that theatrical performance is also an artistic proposal made to the audience and emanating from an aesthetic decision endorsed by artists. Furthermore, the author considers the theatrical phenomenon as an interplay of oppositions and contradictions, a site for social and aesthetic performance, and also as a dynamic space with the appearance of everybody in front of an audience, that is judging and is being judged.