Rita Dove's sonnet cycle, "Her Island," a crown of sonnets finishing the collection Mother Love that in 2005 she said in an essay in This Is My Best was her favorite work.
I don't think I can, in a blog post, tell you all the reasons why this is an amazing poem cycle. I'll hit on a few:
The form so perfectly fits the content. Dove talks in another essay about the allure of the sonnet, putting a white picket fence around disturbing emotions. The collection, a treatment of the Demeter and Persephone myth, explores confinement, rape, loss, the struggle between mother and daughter, generational cycles, and the different kinds of violence a sexual relationship can contain. The sonnet, and the specifically the crown of sonnets with it's repeating lines, is a perfect container for these themes--circling back around the literal lake where the myth places the kidnapping of Persephone and also circling through the cycle of loss, recovery, and change. It's a freaking amazing poem and when I read it in college it blew my mind.
Would you like to write a crown of sonnets? I tried a heroic sonnet one time and I've got to tell you, this is not easy. What I gleaned from Dove's essay linked to above, in This Is My Best, is that this kind of poem is best tackled after you've spent a significant amount of time with the subject, working it out through poems as Dove does throughout her entire Mother Love collection. By the time she gets to "Her Island," she has seen meaning accrete through the different poems she's written--she's seen patterns emerge, she's connected to it in increasingly personal ways as one must as she nears completion of a collection. And then the fabulous capstone coalesces!
If you're nearing the finish line of a collection, a sonnet crown might be a great exercise. It may have to come out of form, may only yield a title poem or a last poem. But the circling energy of the sequence forces the multiple angles of exploration that have an effect of a concluding paragraph in a persuasive essay.