Small ternary form
"Small ternary" is really where I kinda blur the lines between small structure form vs. large structure form. It's basically ternary form but with phrases. It's an ABA structure.
Caplin describes it as "one of the most important forms in all of classical instrumental music".1
Structure
In classical music
The first A section is the exposition. It should end with either a half cadence or an authentic cadence.
The B section is the contrasting middle. It should be similar but create contrast with the preceding A section. It should also end with a half cadence. (Dominant harmony is common to move to here.)
The second A section is the recapitulation. It may not be an exact repetition of the original A section: some material may be cut.
Both the A and B sections can utilize different kind of small structure forms in themselves. For example, the A section could be a period and the B section could be a sentence.
In video game music
(to be written)