
Kyrielle

The kyrielle is a poetic form that originated in troubadour poetry.
Name and form.
The name kyrielle derives from the "Kýrie", which is part of many Christian liturgies. A kyrielle is written in rhyming couplets or quatrains. It may use the phrase "Lord, have mercy", or a variant on it, as a refrain as the second line of the couplet or last line of the quatrain. In less strict usage, other phrases, and sometimes single words, are used as the refrain. Each line within the poem consists of only eight syllables. There is no limit to the number of stanzas a Kyrielle may have, but three is considered the accepted minimum. 
If the kyrielle is written in couplets, the rhyme scheme will be: a-A, a-A. There are a number of possible rhyme schemes for kyrielle constructed in quatrains, including a-a-b-B, c-c-b-B and a-b-a-B, c-b-c-B (uppercase letters signify the refrain). In the original French kyrielle, lines were generally octosyllabic. In English, the lines are generally iambic tetrameters.
An example.
This kyrielle is by Thomas Campion.
"A Lenten Hymn "