Every song in The Collection of Average Rhythm Piano Music includes a prelude and a fugue, which proves the feasibility of average rhythm in keyboard music and the superiority of artistic creation with 24 major and minor sounds. In the first episode, almost every prelude consciously solved a certain skill in performance and introduced a type of keyboard instrument creation. And each fugue also provides the possibility of writing methods of fugue, and all of them have distinct musical personality and perfect music development logic. When other tuning methods were used at that time, Bach wrote this set of works with the average law, which fully reflected his sensitivity and the significance of this set of works. They are classics of keyboard art, which can be called the Old Testament of piano, and compete with Beethoven's 32 piano sonatas (called the New Testament of the Bible).