What poetic form consists of 19 lines, five tercets and a quatrain?

A villanelle is a fixed poetic form consisting of 19 lines arranged as five tercets followed by a concluding quatrain. Its defining feature is the repeated use of two refrains and two rhyme sounds.

The first and third lines of the opening tercet return alternately at the ends of later tercets. Both refrains then appear together in the final quatrain, producing the form’s characteristic circular, insistent music. There is no single mandatory meter, although English villanelles are often written in iambic pentameter.

The form’s history is more complicated than its neat modern pattern suggests. The word derives from the Italian villanella, associated with rustic song, but the strict 19-line structure developed in French poetry. Jean Passerat’s 1606 poem “Villanelle” helped establish the repeating-refrain model later treated as standard.

Two famous English examples are Dylan Thomas’s “Do not go gentle into that good night” and Elizabeth Bishop’s “One Art.” Their repeated lines show how villanelles can turn formal recurrence into emotional pressure, obsession, or gradual change in meaning.