Atonality Theory: Symmetry Theory And Pitch Class Set Theory

This paper focus on the two systemized and influential atonality theories, the symmetry theory and the picth class set theory. According to the standards which are "to confirm and revert the material" and "representation and establishment of centricity" of the pitch orgnization, through analysing the tonal characters of the pieces which belongs to all sorts of genres and theories in the twentith century, the author try to discuss the representations of "tonality" in the twentith century and what along with the relation between "tonality" and "atonality". After a brief viewing of post-tonal theories, the paper will expound the characters of material and structure of both theories, "symmetry theories" divided into "symmetry of pitch orgnization of the post-tonal music", "cyclic set", "twelve-tone tonality", while "pitch class set theory" divided into "pitch class set as the basic material", "the relations among pitch class sets" and "set complexs and structure function". Through comparing the two theories, the paper will discuss "the structure function of interval material", "centricity" and "symmetry" which show influence in the traditional music theories, so can have further acknowledge about "atonality" music and theories, and the status and values of pitch theory in analysis practices and theories.