Unity Through line and Sub-Text

More so then in then in a straight magic act,a dramatic productions structure must have unity. This is best defined by Aristotle's definitions relating to Greek drama, "...( the work should be ) one an entire; the parts being so connected that if any one of them should be taken away the whole act will be destroyed or changed. for whatever may be retained or omitted, without making any sensible difference, is not properly a part." The magic must be an integral part to achieve this unity.
What carries this artistic unity is what is called a throughline, which is this intangible thread that runs through the piece by which the emotional content of the play hangs. Allied to the cause of artistic unity is the sub-text which is what the work is about, but on a deep and emotional or conceptual level. The play is outwardly about two lovers, yet the sub-text may be about the nature of human love it self, etc...