Here's why:
* Easy to Recite: Ballads often have a simple rhyme scheme (usually ABAB or ABCB) and a regular, strong rhythm, making them easy to memorize and recite.
* Repetition: Ballads frequently use repetition of lines or phrases, particularly in the refrain, which helps to solidify the story in the listener's mind.
* Narrative Focus: Ballads are narrative poems, typically telling a story with a clear beginning, middle, and end. This focus on storytelling made them particularly popular with minstrels who traveled and performed for audiences.
Other poetic forms that might fit:
* Folk Song: Folk songs share many of the same characteristics as ballads, often being passed down orally.
* Rhyme Royal: This form, popular during the Middle Ages, also has a strong rhythm and rhyme scheme.
While the exact form might vary depending on the specific minstrel and time period, ballads are the most likely answer to your question.