A sudden thought this morning: what about organizing the course, not by secondary source, but by genre?
Teach a class with units on poetry, literary fiction, popular romance, fantasy, SF, and detective fiction?
Or skip the lit fic, and just do popular genres: romance, fantasy, SF (separate category?), and detective fic. Maybe chick-lit as something separate from romance; maybe the middle-brow bestseller as its own category, too.