Francesca da Rimini (projected opera)
On 10/22 February 1876, Tchaikovsky told his brother Modest that "I'm wavering between Ephraim and Francesca, although I think the latter takes precedence" . On the same day he wrote to Konstantin Zvantsev, asking for "a fresh copy of your charming libretto" . According to Nikolay Kashkin, "Tchaikovsky was very interested in K. I. Zvantsev's libretto for Francesca da Rimini, carefully considered it, and was on the point of taking up composition of the opera, but the librettist suggested certain conditions, with which the composer could not agree. Their differences were not connected with the financial arrangements, but with the interference of the librettist in the composer's working methods. Pyotr Ilyich told me that K. I. Zvantsev was a fanatical admirer of Wagner, and he wanted the composer to write his Francesca in complete accordance with Wagner's reformist theories; he even wanted some kind of right of control for himself in this aspect" .
Because of these creative differences, the opera was abandoned, although later in 1876 Tchaikovsky wrote an orchestral fantasia on Francesca da Rimini.
In May 1877, Herman Laroche sent Tchaikovsky his own libretto for an opera based on Francesca da Rimini. However, by this time the composer had just taken up the subject of Yevgeny Onegin for his next opera, and he never made use of Laroche's text .