12 bar blues

Thomas told me about a book written attempting to abolish the 5-paragraph essay. He did not approve.

You might as well try to abolish the 12-bar blues, I said.  That is not to say that all music will be in this form, or in some other given standard form like the 32-measure AABA or ABAC form of a jazz standard. But if you are teaching someone to be a rock / r and b / jazz or country musician, that form will come up a lot. The five paragraph essay is simply the shortest form of formal expository prose of more than one paragraph. Four won't work, because then the two paragraph in the middle will be equal to the first and last, and so the structure will be unbalanced.