I think it might be beneficial if I write this down, gather my thoughts a little. This is what/how I'm reviewing the rambling ideas rambled about last class.
Context: Think of this like an inside joke. You and your group of friends have the stupid things you say to one another that garner guffaws and uncontrollable giggles. Let's say one of these "code" phrases is "Macaroni Salad." For whatever reason, be it film quote, past experience, something one of you witnessed, these two words send you and your friends into a fit of laughter. In the context of you and your friends, this is funny.
Now, let's put you in a room with a potential boss, interviewing you for a job. You say "Macaroni Salad" to him, and he might simply ask you to leave. The context has changed: instead of your friends, who know how your brain works and have shared similar experiences with you, this interviewer does not know you, does not know how your brain works, and just might be wondering if you always spout out random picnic offerings.
Let's change the context again: You are now in a restaurant, staring into the face of your disgruntled waiter. Say "Macaroni Salad" to him, and he will either write down your order with a bored expression, or his face might scrunch as he says, "Um, we don't have that."
Context can be thought of as the "setting." Change the setting of a reader--what they like, when they read it, etc.--and the meaning of the essay, story, poem can change.
Discourse goes hand-in-hand with Context. Take a look at the "Macaroni Salad" example again. Same word in all three instance, yet it means very different things. To your friends, it conjures up an image of Melinda shooting a noodle out of her nose. To the interviewer, it conjures up an image of you in a mental institution, complete with straight jacket. To the waiter, it's just another order of something they may or may not have. Same word, different meaning.
Theme needs a new example. Try thinking of Theme like the categories in a Blockbuster. Each one has been given a "theme" to be included within: Comedy, Sci-Fi/Horror, Romance, Drama, Action/Adventure, Family, etc. According to Blockbuster, these groupings of films all have the same "theme," the same traits that make them belong together: these films will make you laugh, these films are appropriate for all ages, and so on and so forth. By finding the similar traits, one can pick out a common "theme" among them, and have a general idea of what to expect when plucking a film from its shelf.
But what happens when a film has multiple "themes" that it can fall under? This is where context comes back in: depending on where a film is placed, you expect different things from it.
Take Pirates of the Caribbean: it is, most likely, shelved under Action/Adventure. This makes sense because of its high-seas adventures, sword fights, and exotic location. Someone renting this film and hoping for an adventure, would not be disappointed, because it has been placed under the context of Action/Adventure--even though it has elements of horror, comedy, drama, and romance. What would happen if a Blockbuster employee decided it needed reshelving? If placed in the Horror section, a renter might be annoyed because they didn't find the film scary or gory enough to be a Horror flick. Same goes for Romance. Sure, there is the idea of "romance" between Will and Elizabeth, but had someone rented it from the Romance section, would their ideas of a "Romance" film have been fulfilled? I doubt it. The same goes for comedy. If you were watching this film, having pulled it from the Comedy shelf, you might've expected something along the lines of Robin Hood: Men in Tights, only with swashbucklers instead of outlaws. (Granted, you might still laugh at some of the lines and moments or even the ridiculousness of the film as a whole, but it might not fill your expectations.)
Theme establishes the through-line of a story or essay. It's what pulls all of these elements--different as they might be--together. Good themes should not change, no matter what the context. Readers should be able to recognize a theme, despite its presentation or what prejudices they might bring. (Like Pirates, someone watching it as a Horror film would probably be thinking, "This isn't a horror; it's more of an Action/Adventure.") Theme binds writing together AND it's what gives the universality quality that allows anyone, anywhere to pick up the writing/film/artwork and understand it.
And that's the lesson for today, folks. Let me know what you think, and/or I would be much obliged to know how you present this type of thing yourself. I have a feeling that this will need to come up more than once or twice for students to fully grasp this idea.