A villanelle is a poetic form. It is very formal and tells a story. So, what is the difference between a poem and a villanelle? A poem can be as long as the poet wants it to be, a villanelle has a fixed verse form and has a more detailed and strict structure. Many poets avoid this form as it is very technical but some take this as a challenge and deliver a beautiful villanelle. Some of these poems are very famous and even used in movies like Interstellar!
Do Not Go Gentle Into That Good Night by Dylan Thomas is an example of a villanelle. In each tercet, he progressively describes how different men – wise, good, wild, and grave men – face death. It is only at the last quatrain that we realize that this is targeted towards his father, most likely who is on his deathbed. Dylan Thomas does not want his father to give up and die without a fight.
One Art by Elizabeth Bishop is another example of a Villanelle. In this poem, we are guided in the art of losing things. The poet starts by encouraging us to lose simple items such as door keys or time. She then progresses to talk about losing items of sentimental value, such as a mother’s watch, and then items of possible monetary value such as a house, a river, and a continent. The crux of the matter, however, is when she describes losing a lover in the same terms as losing other items – and inverts the description so that it is clear to us that this was a great loss.
For more information see Wikipedia.