Moreover, it is the presence of the audience which is the final key ingredient of all performing arts. This is particularly true for theatre because its audience is not watching and listening to an abstraction like movement or sound, but human beings like themselves experiencing familiar moments of life. Studio arts such as painting, sculpture, and photography are largely singular activities. That is, only a single artist is necessary to conceive and execute the work to completion. This not the case in dramatic art.
Theatre is an interpretive art.
Conductors, musicians, choreographers, and dancers are interpreters in their respective arts as well, but interpreters of theatre have much greater latitude for personal expression. This is true because the language of drama is much less exact than that of music or dance. Human life is much too complex for any system of notation to describe it completely. Playwrights have only the speech of their characters to carry all the information of a life lived. The interpreters are expected to fill in the blanks.