French opera composer often called ‘the French Mozart’ (1775–1834). Boldly penned ALS in French, signed “Boieldieu,” one page, 5 x 8, June 13, 1831. Untranslated letter mentioning a “convention diplomatique.” In fine condition, with intersecting folds, a few creases, and insignificant paper loss to lower right corner tip. RR Auction COA.