I think it's the history of music, because the breadth of the introduction to art is relatively large, that is to say, the scope involved is relatively wide, and it is difficult to tell it well.

In contrast, the history of music is much simpler. Once it comes to the teaching of "history", there are many unchangeable things, so in the long run, its teaching is much simpler. Because there is that kind of-once and for all advantage.