The three-voice prelude's principal theme suggests a trill played in slow motion, which links it to the subject of the fugue, whose next-to-last note is an authentic trill. Or so it is upon the initial appearance of the theme in the tenor; as the subject arrives in three more voices -- alto, soprano, and finally bass -- the fingers are far too busy to handle a trill everywhere it should appear. Here, Bach tightly weaves his counterpoint with great expertise, although he may have put in too much time revising and perfecting the fugue's technical aspects for the music's own good; ultimately, it is rather dry compared to many of the other fugues in this set.