Mozart's piano sonatas form a richly diverse and significant part of his instrumental output and span much of his mature composing career, thereby representing a microcosm of the composer's changing style. Part I examines the contexts in which the sonatas were composed and performed, and reviews likely sources of influence. Part II concentrates on the genesis of the sonatas and the sources, which reveals important information about Mozart's compositional process. In Part III the musical style is studied from the standpoint of rhetoric—a discipline featured in numerous contemporary aesthetic and theoretical textbooks on music.