The first person to truly appreciate Tchaikovsky's talents was the Italian singing instructor Luigi Piccioli, who influenced young Pyotr so much that he developed a lifelong passion for Italian music. Wolfgang Amadeus Mozart's Don Giovanni had a great impact on him that deeply affected his musical taste. When St. Petersburg Conservatory opened in the fall of 1861, Tchaikovsky was among its first students. That same year, he attended classes in music theory taught by Nikolai Zaremba at the Mikhailovsky palace (now the Russian Museum) in St. Petersburg. After making the decision to dedicate his life to music, he resigned from the Ministry of Justice, where he had been employed as a clerk.
From 1862 to 1865 he studied harmony and counterpoint with Zaremba. Rubinstein who was the director and founder of the Conservatory, taught him instrumentation and composition. One of his earliest orchestral works was an overture entitled The Storm (1864), a mature attempt at dramatic program music. His works were first premiered in August 1865, when Johann Strauss the Younger conducted Tchaikovsky's Characteristic Dnaces at a concert in Pavlovks, near St. Petersburg. In 1868, Tchaikovsky's First Symphony in G Minor (composed in 1866) was well received by the Moscow public, the following year, his first opera The Voyevoda, made its way to the stage.
In March 1871 the audience at Moscow’s Hall of Nobility witnessed the successful performance of Tchaikovsky’s String Quartet No. 1 (1871), and in April 1872 he finished another opera, The Oprichnik, premiered in 1874. By this time, Tchaikovsky had also earned praise for his Second Symphony (1873). After traveling to Paris (1876) with his brother, Modest, he visited Bayreuth, where he met Liszt. By 1877, Tchaikovsky was an established composer. This was the year of Swan Lake's premiere and the time he began work on the Fourth Symphony (1877-1878).
In his attempt to focus his efforts entirely on composing, he resigned from the Moscow Conservatory in 1878. As a result, he spent the remainder of his career composing more prolifically than ever. Early in 1878 he finished several of his most famous compositions: the Eugene Onegin opera, the Symphony No. 4 in F Minor, and the Violin Concerto in D Major. His popularity soon grew both within and outside of Russia which resulted in public interest in him and his personal life.
Over the next 10 years Tchaikovsky produced his operas Mazepa (1883; based on Aleksandr Pushkin’s Poltava) and The Enchantress (1887), as well as the masterly symphonies Manfred (1885) and Symphony No. 5 in E Minor (1888). His other major achievements of this period include Serenade for Strings in C Major, Opus 48 (1880), Capriccio italien (1880), and the 1812 Overture (1880). In both 1888 and 1889, Tchaikovsky went on successful European tours as a conductor, meeting Brahms, Grieg, Dvorák, Gounod, and other notable musical figures. Sleeping Beauty was premiered in 1890, and The Nutcracker in 1892, both with success. Throughout Tchaikovsky's last years, he was continually tormented by anxiety and depression. Following his trip to Paris and the United States in 1891, he had one dark nervous episode. He died 10 days after the premiere of his Sixth Symphony ”Pathétique” in October 1893.
American music critic and journalist Harold C. Schonberg wrote of Tchaikovsky's "sweet, inexhaustible, supersensuous fund of melody," a feature that has ensured his music's continued success with audiences. Tchaikovsky’s approach to solo piano music, on the other hand, remained mostly traditional, that is, it more or less satisfied the 19th-century taste for short salon pieces with descriptive titles, usually arranged in groups, as in the famous The Seasons (1875–76). In several of his piano pieces, Tchaikovsky’s melodic flair surfaces, but on the whole he was far less committed when composing these works than he was when writing his orchestral music, concertos, operas, and chamber compositions.
It cannot be denied that the quality of Tchaikovsky’s oeuvre remains uneven. Some of his music is undistinguished—hastily written, repetitious, or self-indulgent. But in such symphonies as his No. 4, No. 5, No. 6, and Manfred and in many of his overtures, suites, and songs, he achieved the unity of melodic inspiration, dramatic content, and mastery of form that elevates him to the premiere rank of the world’s composers.
Here you can find a list of Pyotr Ilyich Tchaikovsky's compositions.