Music, dance and theatre are created in front of an audience so are known as the performing arts . Theatre then is a performing art, one of the fine arts. Each of the arts has a medium which distinguishes it from the others. The medium of dance is human movement, the medium of music is sound, and the media of sculpture may be stone, metal or wood. It is human beings in the action of life.
Most artists work primarily in one medium, but they do have to choose a subject each time they work.
For the art photographer the subject may be anything within the field of the lens- animals, trees, clouds, people, or the chrome fender of a motorcycle. This extreme diversity of subject matter is true for all the visual arts, but less so for the performing arts, and not at all for the theatre. Of course not. The intention is to use cats as an artistic lens through which to view some aspects of the human experience. The art of the theatre is unique in several important ways.