History:

One of four types of Cywydd, a Welsh metrical form originating in the 14th century, and one of three predominant Welsh metrical forms, the other two being the Awdl, and the Englyn. The other three forms of Cywydd, as listed by Einion Offeiriad around 1320, are Cywydd Deuair Birion, Cywydd Deuair Fryion, and Cywydd Llosgyrnog. 

Structure:

  • quatrain (four line stanza) of seven syllable lines
  • a stanza form
  • Lines 2 and 4 rhyme
  • Lines 1 and 3 cross-rhyme int the 3rd, fourth or fifth syllable of lines 2 and four
  • The middle line rhyme in lines 1 and 3 function as a caesura in the line
  • The mid-line rhymes can be various forms of half-rhyme, such as consonance or assonance. The main rhyme should be perfect
  • The thing to remember about Welsh poetry is that the sonic aspect is central, to facilitate remembering it, which was the central function of the bard-remembering potentially hundreds or more of poems
  • Here’s a possible scheme: 

x x x x x x a
x x a x x x b
x x x x x x c
x x x x c x b

Sources:

http://www.thepoetsgarret.com/celtic2.html#awdl

Koch, J. T. (2006). Celtic culture: a historical encyclopedia. Santa Barbara, Calif. (ABC-CLIO): Cop.

Turco, L. (2012). The book of forms a handbook of poetics, including odd and invented forms. Hanover (New Hampshire): University Press of New England.