As is noted in the introduction to Song of Solomon, there are many different interpretations on what this book means. Ordinarily this wouldn’t change the way that a book is outlined but in this case, this outline is based on the premise that this is a literal wedding that takes place.
The entire book falls under a structure that is known as a chiasm. As noted in the section on Hebrew poetry, ideas are often repeated. This also happens in a chiasm except the repetition comes across a broad section, in this case the entire book.
English poetry has a rhyming pattern that would look something like ABABCDCD. In a chiasm there is no concern for rhyming but the ideas are paired together. Rather than pairing the ideas together ABABCDCD, the ideas are laid out and then repeated back in reverse order – ABCDDCBA.
One of the key features of a chiasm is that the most important idea is not presented at the beginning or the end but in the middle. In this Song of Solomon, the most important part is chapters 4-5 which contains the wedding and the wedding night.
Song of Solomon 1-3: Falling in love, descriptions of the lovers
Song of Solomon 4-5: The wedding and the wedding night
Song of Solomon 6-8: Descriptions of the lovers, remaining in love