Poetry

Terza Rima: 

A form of poetry that uses iambic tercets. Terza Rima uses an "ABA BCB CDC" rhyme scheme and in order to link the stanzas together. At the end of the poem, the rhyme scheme is "XYX YZY Z." Dante's The Divine Comedy was the first poem written in terza rima. In English, it is usually written in iambic pentameter and the poem can be any length, there is not strict line limit. The tercets have often been used to symbolize the Holy Trinity, again originating with Dante's The Divine Comedy.  

Villanelle:

A villanelle has a very strict structure. There must be nineteen lines and contain repeated rhymes and refrains, two each. Villanelles have five tercets and end with a quatrain. The first and third lines of the first tercet are used as the last lines of the following stanzas, in an alternative fashion. This is represented by: AbC abA abC abA abC abAC. This form is derived from French poets that used the name Villanelle to describe their subject matter, idealized portrayals of country life with rustic themes. These poets did not follow the strict rules that Villanelles were later given. 

"Do not go gentle into that good night" by Dylan Thomas 

Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.

Though wise men at their end know dark is right,
Because their words had forked no lightning they
Do not go gentle into that good night.

Good men, the last wave by, crying how bright
Their frail deeds might have danced in a green bay,
Rage, rage against the dying of the light.

Wild men who caught and sang the sun in flight,
And learn, too late, they grieved it on its way,
Do not go gentle into that good night.

Grave men, near death, who see with blinding sight
Blind eyes could blaze like meteors and be gay,
Rage, rage against the dying of the light.

And you, my father, there on the sad height,
Curse, bless, me now with your fierce tears, I pray.
Do not go gentle into that good night.
Rage, rage against the dying of the light.

Dylan Thomas' "Do not go gentle into that good night" is a Villanelle. "Do not go gentle into that good night" and "Rage, rage against the dying of the light" are the two refrains that are repeated. Each of these lines are a powerful, and emotional. This is a truly great feat to accomplish with a Villanelle in the English language because if its strict form. The inevitability of old age and death is one of the main themes of this poem. This is not a poem of despair, but a call to arms. Thomas is urging those that are near the end to go out with a bang, not fade away into nothing. The ending quatrain brings in his person connection with the mention of his father. He implores him to not give up the fight, but to "rage against the dying of the light." 

Sestina:

Sestina poems use a lot of repetition. They have 6 6-line stanzas, sestets. They have 39 lines and no set length for the individual lines but a very strict repetition pattern.  ABCDEF FAEBDC CFDABE ECBFAD DEACFB BDFECA ECA (or ACE). The last three lines are called the envoi and it also has to include BDF words within the lines. Instead of a rhyme scheme, Sestinas use this repetition of the last words of the lines for a semi-rhyme.