 Rousseau’s Letter on French Music (1753) may be seen as an episode in the so-called querelle des bouffons, a dispute concerning the relative merits of Italian and French opera that was prompted by the 1752 Paris performance of Giovanni Battista Pergolesi’s La serva padrona. In the Letter, Rousseau takes the side of Italian music, holding that its superiority over French music is ultimately due to the Italian language, which is more melodious and better articulated than French. French music attempts to address the shortcoming of its language by adopting complex harmonic structures, but Rousseau believes that this only further hinders its expressive potential. He observes how Italian music is more moving not in spite of its use of chords that are not completely filled out, but precisely because of this feature. In the Letter, Rousseau also develops the principle of “unity of melody” (unité de mélodie), according to which music ought to present the listener with one single salient melody at any time, the other voices playing a subsidiary and supportive role. It is from this melodic unity that music derives its capacity to move the listener, and in this resides music’s value. The concept of unity of melody is further elaborated in a dedicated entry of Rousseau’s Dictionary of Music (1768), where he also states that his Devin du Village was an attempt to put that principle into practice (Rousseau 1768, “Unity of Melody”; on unity of melody, see Riley 2004: chapter 2, and Waeber 2009).