The sestina is a medieval provencal poetic form attributed to the troubadour Arnaut Daniel. It consists of six six-line stanzas, ending with a three-line envoi. The six words that end the lines of the first stanza are repeated as the end words of each of the other stanzas in a complex pattern that goes like this (note that each letter corresponds to an end word, not an end rhyme): abcdef, faebdc, cfdabe, ecbfad, deacfb, bdfeca. Each line of the three-line envoi must end with one of the end words but also must contain within it one of the other end words. There are several possible patterns for the envoi, but the most common are ace or eca for the end words and bdf or fdb for the middle words. Since the same words are repeated throughout the poem, the sestina is an excellent vehicle for meditation on complex and multiple meanings.