What is a vianelle poem?

A villanelle is a complex rime and refrain structured verseform derived from medieval models by a fairly complex process of mistaken understanding in Nineteenth Century France, and made popular in Nineteenth Century and Twentieth Century English poetry.

It is difficult to define a villanelle, but very easy to demonstrate what one is by example:

: 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 learned, 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.

The rimepattern and the repeated lines are both required by villanelle form - though there is considerable freedom in the metre used.

The best way to find out about villanelles is to write a few - trying to precisely define one is a headache.