In which the Meridian attempts to determine proper fodder for the Canon

It's a Friday; I and my colleagues who teach Humanities are discussing new texts and assessments for the Humanities survey classes. Every once in a while in our conversation, a vague Something surfaces and stays a bit longer at said surface before sinking again. Finally . . .
I: It seems that we just can't do much more than sorta talk about Cubism at the end of HUM II.
Esteemed Colleagues: Correct!
I: We can't even get to WW I, much less beyond.
Esteemed Colleagues: You betcha!
I: We really could use a HUM III course!
Esteemed Colleagues: Yeah!
I: It could start with Impressionism!
Esteemed Colleagues: Yeah!
I: And it could include film!
Esteemed Colleagues: Of course! Why wouldn't it?? (though someone murmurs, "You gotta be careful with Birth of a Nation.)
I: And music!
Esteemed Colleagues: They gotta hear Barber's Adagio for Strings!
I: I'll write it up! I don't have anything better to do . . . except watch basketball.
Esteemed Colleagues: You go right on ahead and write up something and we'll have a look at it! We're behind you all the way!!
I (thinking): Is that sotto voce snickering I hear?
. . .
I (several hours later, ruefully, during the Big XII quarterfinals): Suckuhhhh!

Some of the above is invention but, as the writers sometimes say, it is in its essence true. This task I've set for myself is pretty damned hard, for two reasons.
I should say for the record that I very much enjoy thinking about the shape and content of programs and individual courses; at my previous institution, unasked, I proposed 3 different outlines for the major/minor in English consisting of existing and new course offerings. But I should also say for the record that I am by nature a Big Picture kind of guy. I could do the sort of stuff I did at my past place of employ precisely because the courses I proposed were empty vessels that each instructor would be responsible for filling.
Here, though, writing the Course Outline is something a Details Person would adore: the writer doesn't just describe the course, s/he also gets to determine its actual contents (subject, of course, to his/her colleagues' approval). Not just Artistic Movements, but who IN those Artistic Movements gets name-checked. So, there's my first dilemma: Am I leaving anything/anybody out that should be in? It's rather like the NCAA Men's Basketball Tournament Committee's deciding from among "bubble teams." The second is a different manifestation of the sort of question that some of us literature types get asked every once in a while and is fun to think about but is really impossible to answer: "Who is writing/painting/making films/making music/etc. now that will be remembered 100 years from now?" The version of that question for this class is, "Who and what, in a survey class for the period from 1870 to the present, should/must students in America's heartland know something about?"
For me, at least, that question is fairly easy till I start thinking about post-WWII things. Then personal taste becomes harder to fight against; then I begin to realize just how beholden to critical opinion I am and how, relatively speaking, there's just less of that to go on that is truly helpful, since the critics, though they've seen/heard/thought about this stuff more than I have, they have the same trouble, really, that any of us have: How do you know in The Moment (and I would say that here, "The Moment" extends back at least a couple of generations as traditionally defined) that what you're seeing/hearing is worth talking about to a general audience?
And that leads me to a third concern, that of all canons, really: To choose is to some extent valorize that selection once you get past the obvious choices. It's unavoidable. Being that the class is a survey, we can fairly accurately claim that we're just looking at our culture's aesthetic history without passing judgment on its aesthetic value. Sorry, kids--we have no choice but to talk about Picasso if we're gonna be at all faithful to this course's goal. But someone like Matthew Barney? Or Julian Schnabel? What about Gerhard Richter? Even someone like Barnett Newman, who did most of his work in the 50's but still seems hard to place (indeed, if we even SHOULD place him) in relation to someone like Rothko. But/and these are Americans and Europeans. How does one talk about Modernist and Postmodernist art as it manifests itself in Latin America, Asia, and Africa?
Of all the academic problems I COULD have, this is actually a nice one to have. The real point of this post is that it reminds me that, back in grad school, I used to think how absurd it was that some of my colleagues would speak of the Canon as though it were . . . like, well . . . you know.