Nourrit by Rossini, Giacomo Meyerbeer and others, contain orchestral markings which indicate that he could not have been singing in falsetto in his upper register. This was a departure from the practice of earlier male operatic interpreters. As Nourrit's status at the Opéra increased, so did his influence upon new productions. Composers often sought, and usually accepted, his advice. For example, when it came to La Juive, he wrote the words of Eléazar's aria "Rachel, quand du Seigneur"; and he also insisted that Meyerbeer rework the love-duet climax of Act 4 of Les Huguenots until it met with his approval. While at the Opéra, Nourrit received consistent positive reviews for his performances and his popularity led to his appointment as the professeur de déclamation pour la tragédie lyrique at the Conservatoire de Paris in 1827. He had many successful students, including the dramatic soprano Cornélie Falcon. In addition, he was concerned more broadly with the social aspects of singing, particularly with the "missionary" role of the performer. In the early 1830s, he embraced the ideas of Saint-Simonianism and dreamed of founding a grand opéra populaire which would introduce operatic works to the masses. Beside singing and teaching, Nourrit composed and wrote scenarios for ballets at the Opéra de Paris, including the libretto for La Sylphide (1832). Nourrit's fame faded in the late 1830s, however, as new singers gained the favour of the Parisian public. In October 1836, impresario Duponchel engaged Gilbert Duprez, who commanded an exciting high C from the chest, as joint "First Tenor" with Nourrit at the Opéra de Paris. Nourrit accepted this arrangement as a hedge against his falling ill. He sang his Guillaume Tell part exceptionally well with Duprez in the audience on 5 October 1836 but five days later, during La muette de Portici, with Duprez again in the house, he suddenly went hoarse. After the performance, Hector Berlioz and George Osborne walked Nourrit up and down the streets as he despaired aloud and talked of suicide. On 14 October, he resigned from the Opéra. Throughout this vexed period in his life, Nourrit enjoyed success as a recitalist. He was the first to introduce Franz Schubert's lieder to Parisian audiences at the celebrated soirées organized by Franz Liszt, Chrétien Urhan and Alexandre Batta at the Salons d’Erard in 1837. The intimacy of the salon apparently suited him well and although criticized for a weakening voice,