New System of Musical Theory

The New System of Theoretical Music is the second treatise on musical theory written by Jean-Philippe Rameau, and published in 1726.

Rameau completes with this work his Treaty of harmony reduced to its natural principles of 1722, and presents it as an introduction to it.

In the meantime, he became aware of the work of Joseph Sauveur on the harmonic resonance of the sound body, which corroborates, on the level of physics and auditory perception, the principles identified in his first book. The perception of harmonics (or consonances) during the emission of the fundamental sound had also been noted previously by the Jesuit scholar Marin Mersenne.

While the entire theoretical approach of the previous treatise was based exclusively on mathematical considerations, Rameau evoked in his New System the physical phenomenon of harmonic sounds, so to speak "consubstantial" with the fundamental sound. Their inevitable presence is based on Nature and justifies, for the author, the notion of perfect harmony.

“There is indeed in us a germ of Harmony, of which apparently we have not yet noticed: it is however easy to notice it in a cord, in a pipe, etc. whose resonance makes three sounds heard. different at the same time »

and longer:

"A single string resonates all the consonances, between which we mainly distinguish the Twelfth and the Seventeenth major"

that is to say, in addition to the fundamental bass, its fifth and its major third, inseparable elements of the major perfect chord.

“This book was really new. From the first line of the preface, a tone of triumph is perceptible. The good news announced by Rameau: the theories of the Treatise are confirmed by experience. »

The content of this treatise will be developed later in Harmonic Generation.