After rehearsals began on 5 December, Pasta balked at singing the "Casta diva" in act 1, now one of the most famous arias of the nineteenth century. She felt that it was "ill adapted to her vocal abilities", but Bellini was able to persuade her to keep trying for a week, after which she adapted to it and confessed her earlier error. At the opening night, the opera was received with what Weinstock describes as "chill indifference". To his friend Francesco Florimo, on the night of the premiere, Bellini wrote "Fiasco! Fiasco! Solemn fiasco!" and proceeded to tell him of the indifference of the audience and how it affected him.