I think there is a great difference, in that when the poet is reading you get the whole personality of the person, especially if he's a good reader. Whereas a person just sitting gets what he puts into it.
None but a poet can write a tragedy. For tragedy is nothing less than pain transmuted into exaltation by the alchemy of poetry.
But what is drama? Broadly speaking, it is whatever by imitative action rouses interest or gives pleasure.