the anatomy of genre

And another thing:

Genre is not the same as structure. Genres usually have a structure, though there is a certain amount of malleability in the structure for the particular works in a given genre: less for a sonnet than a novel, more for a comedy than a tragedy (and at one point does something stop being a novel and become something else which is novel-like? Difficult.) What distinguishes structure from genre? Do particular genres have a particular kind of content? No. What is there to a piece of writing besides structure and content?

I think a major difference in structure malleability for comedy and tragedy lies in possible length. There can be short comic sketches and long-running comedic TV shows (sit-coms, situational comedies in which the humor of one single situation is examine and re-examined, the same terrain constantly explored; Friends ends when three of the characters move away, because the situation of a group of friends who live near each other is over; and maybe comedy really does move its audience to pleasure only). But tragedy tends to work up to one final dreaded scene in which it all comes falling down - and so it definitely can't be too long, drama can be spun out but not tragedy. And it can't be too short, because a joke simply needs one incongruity, whereas a tragedy needs to develop why the final tragic event is so dreadfu. 

Is I, Claudius a tragedy? Or tragic? Structured differently, structured longer, from a Greek tragedy, the basis of all our notions of the tragic. It's based on a novel, mind ...