A French form of the early Renaissance named after the "Kyrie Elieson" of the Catholic mass. It consists of tetrameter couplets usually joined into quatrains, with the last line (or a portion of the last line) of the first quatrain repeated as a refrain. Thus the rhyme scheme would be: aabB ccbB ddbB, etc. There are, however, numerous variations, such as abaB cbcB, etc., or acaB adaB, etc. This is a form often used for writing hymns.