Creation is the process of the forming logical motion of musical elements,while analysis is the process of distinguishing the logical motion of musical elements.Starting from the motional logic of musical elements,this article elaborates on how to understand the essence of music with Beethoven's first and twenty third piano sonatas,as well as QIN Wenchen's“Pipa Ci"as examples.The emphasis on the “rigor”and“uniqueness"of the motional logic determines the completeness and artistic value of a musical work.