There are a number of reasons why minstrels used the ballad structure. First, ballads were easy to learn and remember. They were typically written in a simple meter, and they often had a repetitive chorus that could be sung along to. Second, ballads were a good way to communicate a story or message to a large audience. They could be performed in public places, such as markets or fairs, and they could be easily understood by people of all ages and backgrounds. Third, ballads were a way for minstrels to earn money. They could perform for wealthy patrons or collect donations from the public.
The ballad structure was a versatile and effective way for minstrels to share their art with the world. It was a simple but powerful form of poetry that could be enjoyed by people of all ages and backgrounds.