If you are referencing a general performance of a play or show, you can refer to it via the author of the play or show being performed and then include specific details to indicate the performance viewed.
This was evident in Ibsen (2012) ...
A contrasting depiction shows the character as... (Ibsen 2012).
AUTHOR SURNAME, Initial., Year of Performance. Title of play/show [live performance]. Dir. INITIAL. DIRECTOR SURNAME. Place of performance [if known]: Performance venue [if known]. Date of performance if known [viewed date]. Available from: Platform name or URL
IBSEN, H., 2012. A doll’s house [live performance]. Dir. C. CRACKNELL. London: Young Vic Theatre. 17 & 18 July [viewed 9 July 2018]. Available from: Digital Theatre Plus