English: Lulli composed the incidental music for a ballet, La Princesse d'Elide, which formed part of Molière's divertissement, “Les plaisirs de l'île enchantée,” written for a great festival at Versailles on the 7th of May 1664. It is among Philidor's copies of Lulli's ballets preserved in the library of the Paris Conservatoire of Music (vol. xlvii., p. 61). One number is “Air des valets de chiens et des chasseurs avec les cors de chasse,” set for five horns in B♭. Here the use of D, the fifth note of the harmonic series, indicates that the fundamental was a tone lower than the C horn and known as B♭ basso. Victor Mahillon (see “Le Cor,” pp. 23 and 24, and Dictionnaire de l'acad. des beaux arts, vol. iv., art. “Cor.”) considers that the music reveals the fact that it was written for horns in B♭, 35 degrees (chromatic semitones) above 32-ft. C, or the note shown in this image having a wave-length of 1.475 m. To this statement it is not possible for Kathleen Schlesinger to subscribe.