This thesis considers all of Ernest McClain's published writings, from March, 1970, to September, 1976, from the standpoint of their present-day acoustical significance. Although much of the material comes from McClain's writings, some is drawn from other related musical, mathematical, and philosophical works. The four chapters begin with a biographical sketch of McClain, presenting his background which aided him in becoming a theoretical musicologist. The second chapter contains a chronological itemization of his writings and provides a synopsis of them in layman's terms. The following chapter offers an examination of some salient points of McClain's work. The final chapter briefly summarizes the findings and contains conclusions as to their germaneness to current music theory, thereby giving needed exposure to McClain's ideas.