These genres are clearly natural fits for each other in practice, but what is it that enables them to work so well together? More broadly, why does genre-crossing work in the first place? First it is necessary to understand genre, a word with two distinct but related meanings. In a classical sense, at least, genre describes structure as much as content. This is true even to the extent that Aristotle, in The Poetics, discussing how epics are distinct from tragedies not just in their plot structure, but in the fact that epics are written in hexameter. That
