But Mercadante's style began to shift with the presentation of I Normanni a Parigi at the Teatro Regio in Turin in 1832: "It was with this score that Mercadante entered on the process of development in his musical dramaturgy which, in some aspects, actually presaged the arrival of Verdi, when he launched, from 1837 on, into master works of his artistic maturity: the so-called "reform operas". The beginnings of the so-called "reform movement", of which Mercadante was part, arose from the publication of a manifesto by Giuseppe Mazzini which he wrote in 1836, the Filosofia della musica. In the period after 1831 he composed some of his most important works. These included Il giuramento which was premiered at La Scala to 11 march 1837. One striking and innovative characteristic of this opera has been noted: ..it marks the first successful attempt in an Italian opera premiered in Italy of depriving the prima donna, or some other star singer, of her until-then inalienable right of having the stage to herself at the end. By doing this, Mercadante sounded what was to be the death knell of the age of bel canto. Early in following year, while composing Elena da Feltre (which premiered in January 1839), Mercadante wrote to Francesco Florimo, laying out his ideas about how opera should be structured, following the "revolution" begun in his previous opera: I have continued the revolution I began in Il giuramento: varied forms, cabalettas banished, crescendos out, vocal lines simplified, fewer repeats, more originality in the cadences, proper regard paid to the drama, orchestration rich but not so as to swamp the voices, no long solos in the ensembles (they only force the other parts to stand idle to the detriment of the action), not much bass drum, and a lot less brass band. Elena da Feltre followed; one critic found much to praise in it: These temporarily put him in the forefront of composers then active in Italy, although he was soon passed by Giovanni Pacini with Saffo and Giuseppe Verdi with several operas, especially Ernani. Later works Some of Mercadante's later works, especially Orazi e Curiazi, were also quite successful. Many performances of his operas were given throughout the 19th century and it has been noted that some of them received far more than those of Verdi's early operas over the same period of time. Throughout his life he generated more instrumental