Task: Question Answering
Input (English): Passage: Tchaikovsky played the finale of his Second Symphony, subtitled the Little Russian, at a gathering at Rimsky-Korsakov's house in Saint Petersburg on January 7, 1873, before the official premiere of the entire work. To his brother Modest, he wrote, "[T]he whole company almost tore me to pieces with rapture—and Madame Rimskaya-Korsakova begged me in tears to let her arrange it for piano duet". Rimskaya-Korsakova was a noted pianist, composer and arranger in her own right, transcribing works by other members of the kuchka as well as those of her husband and Tchaikovsky's Romeo and Juliet. Borodin was present and may have approved of the work himself. Also present was Vladimir Stasov. Impressed by what he had heard, Stasov asked Tchaikovsky what he would consider writing next, and would soon influence the composer in writing the symphonic poem The Tempest.What endeared the Little Russian to the kuchka was not simply that Tchaikovsky had used Ukrainian folk songs as melodic material. It was how, especially in the outer movements, he allowed the unique characteristics of Russian folk song to dictate symphonic form. This was a goal toward which the kuchka strived, both collectively and individually. Tchaikovsky, with his Conservatory grounding, could sustain such development longer and more cohesively than his colleagues in the kuchka. (Though the comparison may seem unfair, Tchaikovsky authority David Brown has pointed out that, because of their similar time-frames, the finale of the Little Russian shows what Mussorgsky could have done with "The Great Gate of Kiev" from Pictures at an Exhibition had he possessed academic training comparable to that of Tchaikovsky.). 
Question: What is the name of the person who wrote to his brother stating, "the whole company almost tore me to pieces with rapture"?
Output (English): Tchaikovsky.