Sentential period
A sentential period is a kind of grammatical theme defined and described in richards-2016. It can be split up into 2 phrases: the presentation and the consequent.
Note that the repetition of the basic idea, A', must differ from the basic idea itself.
The 2nd A must be more similar to the first A than A' is. This makes it feel like a period.
This form type is not commonly used in film music, though there are some prominent examples (below). (richards-2016 par.38)
Examples
The Pink Panther main theme
Raiders of the Lost Ark main theme
The Informer main theme
