I started the summer series with the 19th century Realism of Manet in the 1860s because that's where the development of abstraction begins: with the flattening of the picture plane. (After all, after the invention of the camera in 1839, painters were freed to move away from realism.) I wanted to show the reasoning behind abstraction for those who dismiss it too quickly.
I was originally a little nervous about the series. Now I can't imagine that that was true. It's been so much fun.
I think that when one teaches art, you really need to add art history to the studio classes. One of my colleagues also adds studio projects to the art history classes (like drawing perspective) but I have so much to say about the art history that I just don't make time for it. But I do show cubist, expressionist and surrealist slides for my painting classes and a variety of other things for my drawing classes. As you noted, it makes their own art so much richer.