All the leading performers distinguished themselves, and Sophie covered herself with glory. “Mlle. Arnould,” says the _Mercure_, “charms as much as she astonishes us in the rôle of Iphigénie, by her dignified and sympathetic acting, by the animation and correctness of her singing, by an expression always true and delicate; by her voice itself, which seems in this opera to possess more variety, power, and extent.” Grimm, a far less partial observer, where Sophie is concerned, than the musical critic of the _Mercure_, is equally enthusiastic: “She renders the part of Iphigénie as it has perhaps never been rendered at the Comédie-Française, and she sings not only with all the charm that we have found in her for a long time past, but with an infinite precision, which is less common with her. It seems that the Chevalier Gluck has exactly divined the character and range of her voice and has assigned to it all the notes of her part.”[50] _Iphigénie_ grew in favour with each repetition and soon became quite the rage, as a proof of which may be mentioned the fact that the ladies began to wear a “headdress in the form of a coronet surmounted by the crescent of Diana, whence escaped a kind of veil that covered the back of the head; it was called _à l’Iphigénie_.” Encouraged by the success which had attended _Iphigénie_, Gluck at once set to work to adapt _Orfeo_, the most successful of the operas he had produced in Italy, for the Paris stage. A good many alterations were necessary, as the title-part had originally been written for a contralto, the celebrated Guadagni, and it had now to be cast for Legros. That gentleman, whose head would appear to have been slightly turned by the applause he had received as Achilles, when handed his part, informed the composer that he should decline to sing it, unless he had an opportunity of making a brilliant exit in the first act; and this necessitated further alterations. However, the rest of the troupe were by this time far more amenable to reason than they had been during the rehearsals of _Iphigénie_, and by the end of July the opera was ready for production.