It seems appropriate for Fiorelle,
Who's in a literary mood,
To write about the villanelle.
And thus would start one of poetry's most convoluted forms, the villanelle. A villanelle is five three-line stanzas plus a sixth, four-line stanza. The rhyme scheme is aba for the first five stanzas, then abaa at the end. In other words, the first and third lines of each of the three-line stanzas rhyme throughout the poem, and all the second lines of each stanza rhyme with each other.
Duck soup, you say, but there's more. The first line of the first stanza is repeated as the third line of the second, fourth, and sixth stanzas; meanwhile the last line of the first stanza is repeated as the last line of the third, fifth, and sixth stanzas.
Wowsie! That means one must come up with a two recurring lines that will make sense throughout the poem, then together will give you a socko ending. And don't forget those other rhymes that have to be worked in. All in iambic tetrameter (four strong beats per line) or pentameter (five strong beats per line).
Fiorella looked over several villanelles, good and bad, before she tried one on her own and realized that her best chance of success was to make a list of something, one item per stanza. Thus, after announcing the Nativity in the first stanza of her Christmas poem, she covered the angels, the shepherds, the wise men, mankind, and the universe in the subsequent stanzas.
The best-known, and I think the best-written, villanelle in literature is Dylan Thomas's "Do Not Go Gentle into that Good Night," which, typical Thomas, sounds good even if you don't understand a word of it. It's a real tour de force. Look it up and note that not only does Thomas adhere to all the rules the Frenchies set for this very challenging form when they invented it, but he also adds another twist by setting up his initial rhymes as polar opposites, "night" and "day."
Fiorella isn't that good yet, but she's done okay. The one she wrote this Christmas is her third, and it's better than her first one, which was better than her second one. Maybe the fourth one, whenever it arrived on the doorstep of her mind, will be better yet.