Rousseau, Jean-Jacques

first octavo edition, [1], xii, 547 & [1] pages, 8vo (19.5 x 12cms), engraved vignette on title, preface, errata-list at end, thirteen engraved folding plates, including a seating plan of the Dresden Opera orchestra, contemporary marbled calf, gilt two-line border, spine gilt in compartments, small crack to letterpiece, some spotting, staining and fraying to edges of folding plates, tear to plate N repaired 

Hirsch, i 521

Condition is described in the main body of the cataloguing, where appropriate.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

'A vital force in determining musical thought in the second half of the [eighteenth] century' (Thomas Hunt). Rousseau's compendium is widely considered the first modern music dictionary. Conceived partly as a corrective to his articles on music for the Encyclopédie by Diderot and d'Alembert, which were completed in haste and contained factual errors, its influence on subsequent works of its kind was profound. Many of the 900 articles comprising the Dictionnaire would reappear, often plagiarised or without acknowledgement, in Panckoucke's Encyclopédie méthodique, Abraham Rees's New Cyclopaedia and Castil-Blaze's Dictionnaire de musique moderne, to name but a few. 

More than a mere reference work, it is an expression of Rousseau's aesthetics, by turns poetic and polemic, strewn with eloquent reflections on the nature of music ("la musique [...] par des inflexions vives, accentuées, &, pour ainsi dire, parlantes, exprime toutes les passions, peint tous les tableaux, rend tous les objets, soumet la Nature entière à ses savantes imitations") and witty critique of his rivals' work (especially that of Rameau, whose complex harmonic theories mistook 'les propriétés des nombres pour celles des sons", Rousseau quipped). In its great rigour, erudition and philosophical depth, it is perhaps Rousseau's finest work of musical scholarship.