There is no doubt that the popularity of ballad can be traced back to ancient folk-literature. It was customary for the minstrels to sing ballads from village to village. Thus it is quite obvious that the ballad means a dancing song and the tradition of singing ballad is quite old.
Another characteristic of a ballad is that it depicts a short story in verse. The theme of a ballad is never complicated. It has simplest theme like exciting adventure, a memorable feud, love and war etc. For example, in the immortal ballad “La Belle Dame sans Merci” by John Keats
The title of this ballad is in French language and it means a beautiful lady without pity. This famous ballad narrates this story tinged with romantic melancholy through dialogue between the poet and the knight wandering all alone in the forest. The poet asks him why he is wandering all alone in the forest as the weather is very cold and the birds have stopped chirping.
The poet further says that the face of the knight seems to be full of sorrow. Keats uses
I see a lily on thy brow
With anguish moist and fever dew,
And on thy cheeks a fading rose
Fast withereth too.
The knight replies that he has been cheated in love by a beautiful but cruel lady. The ballad becomes quite interesting as we come to know that the lady showed her love toward the knight, but in the end she left the poet all alone in the forest. The whole poem is charged with romantic melancholy. The fact is that this cruel lady is a symbol of the eternal female often breaking the hearts of men.
I saw pale kings and princes too,
Pale warriors, death-pale were they all;
They cried—“La Belle Dame sans Merci
Hath thee in thrall!”
It might be added that the poem is autobiographical as Keats was disappointed and frustrated in his love for Fanny Brawne.