Question: Which Russian Composer is the Pyotr Ilyich Tchaikovsky symphonic poem Francesca da Rimini, dedicated to? 
Context: Pyotr Ilyich Tchaikovsky's symphonic poem Francesca da Rimini: Symphonic Fantasy after Dante, Op. 32, was composed in fewer than three weeks during his visit to Bayreuth in the autumn of 1876.  It is dedicated to his friend and former pupil Sergei Taneyev. Pyotr Ilyich Tchaikovsky ( ; Russian: Пётр Ильи́ч Чайко́вский ; 25 April/7 May 1840 – 25 October/6 November 1893), often anglicized as Peter Ilich Tchaikovsky, was a Russian composer of the romantic period, some of whose works are among the most popular music in the classical repertoire.  He was the first Russian composer whose music made a lasting impression internationally, bolstered by his appearances as a guest conductor in Europe and the United States.  Tchaikovsky was honored in 1884, by Emperor Alexander III, and awarded a lifetime pension. Francesca da Rimini (Russian: Франческа да Римини ), Op.  25, is an opera in a prologue, two tableaux and an epilogue by Sergei Rachmaninoff to a Russian libretto by Modest Ilyich Tchaikovsky.  It is based on the story of Francesca da Rimini in the fifth canto of Dante's epic poem "The Inferno" (the first part of the "Divine Comedy").  The fifth canto is the part about the Second Circle of Hell (Lust).  Rachmaninoff had composed the love duet for Francesca and Paolo in 1900, but did not resume work on the opera until 1904.  The first performance was on 24 January (O.S. 11 January) 1906 at the Bolshoi Theatre, Moscow, with the composer himself conducting, in a double-bill performance with another Rachmaninoff opera written contemporaneously, "The Miserly Knight". Francesca da Rimini is a 1901 play by the Italian writer Gabriele D'Annunzio.  It tells the story of how Francesca da Rimini falls in love with her husband's brother in the 13th century. Francesca da Rimini or Francesca da Polenta (1255–ca. 1285) was the daughter of Guido da Polenta, lord of Ravenna.  She was a historical contemporary of Dante Alighieri, who portrayed her as a character in the "Divine Comedy". Sergei Ivanovich Taneyev (Russian: Серге́й Ива́нович Тане́ев , "Sergey Ivanovich Taneyev", ] ; November 25 [O.S. November 13] 1856 – June 19 [O.S. June 6] 1915 ) was a Russian composer, pianist, teacher of composition, music theorist and author. The Tempest (Russian: Буря "Burya"), Symphonic Fantasia after Shakespeare, Op.  18, is a symphonic poem in F minor by Pyotr Ilyich Tchaikovsky composed in 1873.  It was premiered in December 1873, conducted by Nikolai Rubinstein. Francesca da Rimini, Op.  4, is an opera in four acts, composed by Riccardo Zandonai, with libretto by Tito Ricordi, (1865–1933), after the play "Francesca da Rimini" by Gabriele d'Annunzio.  It was premiered at the Teatro Regio in Turin on 19 February 1914, and is still staged occasionally. Pyotr Ilyich Tchaikovsky wrote several works well known among the general classical public—"Romeo and Juliet", the "1812 Overture", and his three ballets: "The Nutcracker", "Swan Lake", and "The Sleeping Beauty".  These, along with two of his four concertos, three of his six symphonies (seven if his program symphony "Manfred" is included), and two of his 10 operas, are probably among his most familiar works.  Almost as popular are the "Manfred" Symphony, "Francesca da Rimini", the "Capriccio Italien", and the Serenade for Strings. Fatum, Op. 77, is a symphonic poem by Pyotr Ilyich Tchaikovsky.  It was written in 1868 and performed in 1869, but Tchaikovsky later destroyed the score, and it was published only three years after his death, with a posthumous opus number.
Answer: Sergei Taneyev