The problem with which this investigation is concerned is the determination of compositional styles in terms of manners of employing monadic and dyadic intervals in the music of the common practice period. An aspect for determining style is proposed by way of comparing the frequency of occurrence of dyads and monads in selected musical examples from the baroque, classical, and romantic periods. Chapter I is a discussion of the problem and methodology of the study. Chapters II, III, and IV present analytic comparison of examples in the baroque, classical, and romantic periods respectively. Chapter V presents a summary of the findings with references to the pedagogical applications of the two-part framework principle.