My reaction to Pat Conner's query is very similar in result to that of
Clifford Flanigan, but rather different in route.  For God's sake don't
begin a discussion of medieval drama by perpetuating the myth of the
glorious development of modern scholarship out of the dark errors
perpetuated by our predecessors!  First of all, the errors in question
have not been the accepted wisdom in scholarship for a long time (let's
say at least since Hardison), and second, the errors as usually
described in retellings of the myth are rather hard to find even in
Young and the other whipping boys of the story.
 
The two most noticeable featurs of Hardison's brilliant polemic against
Young, as I read it fifteen years ago as an undergraduate, were that he
ascribes to Young a blindness to the chronological facts which cannot in
fact be documented from Young's work (Young is quite aware that the
chronology of the manuscripts does not parallel his typology, and
expresses the hope that the typological arrangement may be useful
whether Young's view of etiology is true or not), and that after arguing
at length against Young's evolutionary metaphor (painting Young's
heuristic metaphor as a dreadful Procrustean monster) he counters it
with -- a different view of evolutionary progress, complete with
references to the biological literature to show that biological
evolution, like the literary development he argues for, progresses
fitfully, not by smooth increments.
 
Work in the history of scholarship in other areas (Middle High German)
has persuaded me that the very worst place to learn about earlier
scholarship is in the footnotes of those who cite it:  far too much
distortion and careless reading.  Learn about Young from Young, not
Hardison:  you'll get a rather different view.
 
If you had more time, I'd certainly suggest you talk about origins.
Since the introduction of new genres reflects points of disequilibrium
in literary culture, the question of origins ought to be of great
interest for any account of literature in culture.  Perhaps this view
marks me as a misplaced positivist:  certainly I think more highly of a
lot of nineteenth-century work than I do of a lot of more recent work.
(But I promise, I haven't worked hard at all to remain a positivist!
All it takes is reading some nineteenth- and twentieth-century
scholarship together.)  Clifford Flanigan, to his credit, does not make
the mistake of claiming that interest in origins has somehow been proven
incorrect; he rightly points out that what has happened is a shift of
interest and/or fashion, not a factual refutation of earlier work.
He happens to greet the shift, but does not pretend there are
substantive reasons for doing so.  What does knowledge of origins tell
us that makes any difference, he asks?  Nothing much.  But what will a
knowledge of cultural criticism and the relations of performance to
other contemporary practice tell us that would make any more difference?
Alas, again the answer is, nothing much.  In the long run, we're still
all dead.
 
Despite the intrinsic interest of questions of origin, however, the
origin-of-X is mostly interesting to people familiar with X.  I would
think personally that issues of performance practice, economics, and
placement of the drama in the class and social structure of the time
would be more immediate concerns for the audience you mention.  But if
you have only two days for medieval English drama, you will have your
hands full getting the students to look at and see what is there.
 
The best thing you can ask them to do is to give them some notion of the
social context of the plays and the function of their performance or
written transmission and have your students read, reread, and read once
more.
 
Michael Sperberg-McQueen