These two terms, which may be found in performance analysis theory, for instance, differ in several important respects. Firstly, “Drama” is a very old term, one of the three modes of verbal expression as defined by Aristotle in The Poetics. Aristotle differentiated them by the narrator choice – Verse has one narrator; epic has several narrators; drama has no narrator. In the twentieth century a clear definition was established by Bernard Beckerman (Dynamics of Drama) when he separated theatre from drama: “Drama occurs when one or many present themselves to others in imagined acts.” Here is where “rhythmic activities” can be separated from drama – both are theatrical (presenting oneself to others), but dancing (to use a common word for rhythmic activities) is not imagined. Also, “rhythmic activities” are not verbal; that is, they occur outside the language of “poetry.” The term is much less formal, and much harder to define, since any movement can be said to be rhythmic, if it has repeating elements in it. While some rhythmic activity can be "imitative" action, it need not be.