Ballad metre or ballad stanza is the usual form of the folk ballad and its literary imitations, consisting of a quatrain in which the first and third lines have four stresses while the second and fourth have three stresses. Usually only the second and fourth lines rhyme. The rhythm is basically iambic, but the number of unstressed syllables in a line may vary, as in this stanza from the traditional 'Lord Thomas and Fair Annet':
'O art thou blind, Lord Thomas?' she said, 'Or canst thou not very well see? Or dost thou not see my own heart's blood Runs trickling down my knee?'