Medieval Ballad

The ballad was a musical rhymed meter produced by the common people and recited or sung in alehouses or at fairs. The word ballad came from Latin: in fact these poems were sung to a simple instrumental accompaniment. Popular ballads were anonymous narrative poems, written in short stanzas of two or four lines, rhyming abcb. There is a mixture of dialog and narration, the speaker does not introduce his personality and there is no moralizing or didactic approach.
The types of ballad:

Ballad of magic, about fairies, ghosts, witchcraft and transformation
Border ballad

Ballad of love and domestic tragedy
Ballad of outlaws, for example Robin Hood

Ballad present the narrative not as a sequence of events, but as a series of rapid flashes. The language is simple and often each stanza contains the repetition words or lines, for help the memorization of the text. The repetition of more lines was called refrain.
The ballad universe was peopled with speaking animals, birds, fairies and witch. These characters are magic with supernatural power.

The medieval narrative poem

A narrative poem tells a story in verse and contains a variety of ambient such as the setting in time and place, the description of character. The narrator was often in the first person. Medieval narrative included the exempla, in form of parables and fables, where the moral teaching could be drawn both by real and by fantastic situations. Then there are the fabliau, whose subjects were often-clerical; the romance, a tale in which appear the concept of love and war in a courtly setting. They described the lifestyle, the psychology and the experience of a singular character.
The greatest example of narrative poem was given by Geoffrey Chaucer in Canterbury Tales, a long poem where each tale has meaning in relation to the character of its teller and to the other characters. The tale contains interludes. This poem has a large variety of style