A fugue is built from a short phrase, called the fugue subject. The subject begins in one part and is then subsequently taken up by the others. Baroque composers like J.S. Bach did a lot of it, sometimes in very complicated, chromatic forms, but fugues are found in music from across history, from Beethoven quartets to Shostakovich.
Write an introductory paragraph with a clear topic sentence. The topic sentence sums up the gist of the paper in one sentence. The remainder of the paper lays out the steps of the argument. For example, if the analysis has five essential points, briefly summarize the five steps in the introduction.