This is one of the Great Courses CD sets covering the history of Jazz. It is a good history starting from Cakewalks, an early black form of music combining some African and some European elements. This grew to Ragtime, and ultimately to a variety of forms of Jazz.
One CD is devoted to each style. The discussion covers how it evolved, what elements are unique and what characterizes the style, and how it came to be replaced. There are many music samples and the speaker includes comments on music theory.
The series is full of information and very enjoyable. And it goes fast.