[CHÂTEAU DE LA MUETTE] Camille ÉRARD (1813-1889) née Février, wife of piano maker Pierre Érard, whom she succeeded as head of the Érard firm. L.A.S., La Muette April 16 [1869], to composer and conductor Michael Costa (1808-1884); 1 page in-8 in her own handwriting. She congratulates him on his knighthood: "Galignani's Messenger brings us this morning a news that has caused great joy among all the inhabitants of La Muette and it is in their name as well as in mine that I come to offer you our warmest and most sincere congratulations"... She assures him of her faithful friendship Madame Camille Érard was a friend of the greatest composers of her time, such as Wagner who dedicated his Tannhauser to her.