It just is:

[Erthona]

There is a ballad, and there is ballad meter. A ballad simply refers to a simple or folksy type song or poem, usually either romantic or adventurous. As ballad meter (or verse) is in iambs, and not accentual verse, all syllable are counted. Ballad meter, unlike common meter, has a looser rhyme scheme. xaxa (ballad) instead of abab (common). A stanza is composed of four lines of alternating iambic tetrameter and iambic trimeter. "Amazing Grace" is a good example of ballad meter. Although some consider ballad meter and common meter the same, I think this is because common meter is a subset of ballad meter. Although there is no historical case to be made of this, usually more complex forms follow from less complex forms. My thought is that Ballad meter was present before the Norman invasion of 1066, and common meter came out of a desire for the English writers to sound more courtly, thus more formal, and more exacting. This is supported to some degree by the fact that straight iambic tends to be the syntactical reverse of common English syntax, coming as it did from the West Germanic. All Romance languages, including French have a reversed syntax to English, and so to me it makes perfect sense that writers, while still using English words, would imitate the accentual phrasing of the Norman Court language, Old French. In a sense it is no more than putting on a false accent in order to lend gravitas to ones writing. The one other point of difference between the two types is the exactness in meter. Ballad meter will generally allow half feet and the like, however, the difference in most of the literature as regards one to the other is in the rhyme scheme, not the meter. There is also the fourteener, consisting of iambic heptameter couplets, which is often associated with ballads, and confused with ballad meter. None of this is authoritative, as I am unsure that is even possible, but it does seem a consensus of sorts.

Dale