Burning with desire to remedy the imperfection of his early education, Rameau now diligently studied the writings of Zarlino, Descartes, Mersenne, F. Kircher, and certain other well-known authors. He not only mastered their several theories but succeeded in demonstrating their weak points and substituting for them a system of his own, which, notwithstanding its manifest imperfection, was based upon firm natural principles, and ultimately led to discoveries of the utmost possible value to musical science. His keen insight into the constitution of certain chords, which in early life he had studied only by ear, enabled him to propound a series of hypotheses, many of which are now accepted as established facts; and, if, in his desire to carry out his system to a logical conclusion, he was sometimes tempted into palpable and dangerous error, it was only in obedience to the law which invariably renders the inventor of a new theory blind to the stubborn facts which militate against its universal application. His theory was based upon an instinctive anticipation of the discoveries of modern science. While the older contrapuntists were perfectly satisfied with the laws which regulated the melodious involutions of their vocal and instrumental parts, Rameau demonstrated the possibility of building up a natural harmony upon a fundamental bass, and of using that harmony as an authority for the enactment of whatever laws might be considered necessary for the guidance either of the contrapuntist or the less ambitious general composer. And in this he first explained the distinction between two styles, which, in deference to the views expressed by a popular critic of the present day, have been called the “horizontal and vertical systems,” the “horizontal system” being that by which the older contrapuntists regulated the onward motion of their several parts, and the “vertical system” that which constructs an entire passage out of a single harmony. From fundamental harmonies he passed to inverted chords, to which he was the first to call attention; and the value of this discovery fully compensates for his erroneous theory concerning the chords of the eleventh and the great (Angl. “added”) sixth.

Rameau first set forth his new theory in his Traité de VHarmonie (Paris, 1722), and followed it up in his Nouveau Système (1726), Génération Harmonique (1737), Démonstration (1750), and Nouvelles Réflexions (1752). But it was not only as a theorist that he became famous. Returning to Paris in 1722, he first attracted attention by composing some light dramatic pieces, and then showed his real powers in his first great opera, Hijypolyte et Aricie, founded on Racine’s Phèdre, and produced at the Académie in 1733. Though this work was violently opposed by the admirers of Lully, whose party spirit eventually stirred up the famous “guerre des bouffons,” Rameau’s genius was too brilliant to be trampled under foot by an ephemeral faction, and his ultimate triumph was assured. He afterwards produced more than twenty operas, the most successful of which were Dardanus, Castor et Pollux, Les Indes Galantes, and La Princesse de Navarre. Honours were now showered upon him. He was appointed conductor at the Opéra Comique, and the directors of the opera granted him a pension. King Louis XV. appointed him composer to the court in 1745, and in 1764 honoured him with a patent of nobility and the order of Saint Michael. But these last privileges were granted only on the eve of his death, which took place in Paris on 12th September 1764.