DISCUSSIONS OF THE THEORETICAL SYSTEM of Jean-Philippe Rameau (I16831764) are ordinarily concerned with the origin and significance of the basse fondamentale and related concepts and with Rameau's scientific or Cartesian bias, which served to attract the attention of the philosophes and Encyclopedists. Such discussions often pay insufficient attention to the fact that one of the principal sources of Rameau's system, and probably the main reason for its endurance, was his activity as a composer, performer, and teacher. His stated purpose was always to simplify and thus improve harmonic practice in conformance with the natural, scientific procedures and principles that he had discovered. Traditional methods of continuo realization required an abundance of chords, chord progressions, and rules-rules of doubling, voice leading, and dissonance treatment. But the principle of the fundamental bass-the succession of chord roots-was supposed to make possible a simpler, more natural, and therefore better method of learning keyboard accompaniment and composition. The fundamental bass principle told the performer or composer the key or tonal center of the piece of music, the various keys through which it passed, the functions of the chords, the harmonic rhythm, the lengths of the phrases, and the location of the cadences. In i732 Rameau published a short treatise entitled Dissertation sur les diffdrentes me'thodes d'accompagnement pour le clavecin ou pour l'orgue; avec le plan d'une nouvelle me'thode, ftablie sure une me'chanique des doigts, que fournit la succession fondamentale de l'harmonie : et d l'aide de laquelle on peut devenir sfavant compositeur, & habile accompagnateur, meme sans sfavoir lire la musique1 (Dissertation on the different methods of accompaniment for the harpsichord or organ, with the plan for a new method, based on a fingering technique furnished by the fundamental succession of the harmony, and with the aid of which one can become a knowledgeable composer and skillful accompanist, even without knowing how to read music). By this time his theories were generally known, mainly from the Traite de l'harmonie (1722) and the Nouveau Systkme (1726). He was now fifty years old and was living in Paris. Although not yet known as a dramatic composer (the opera