Question: What group did the composer of Pictures at an Exhibition belong to?

full_context: Document 1: Russian classical music: Russian classical music is a genre of classical music related to Russia's culture, people, or character. The 19th-century romantic period saw the largest development of this genre, with the emergence in particular of The Five, a group of composers associated with Mily Balakirev, and of the more German style of Pyotr Tchaikovsky.
Document 2: Modest Ilyich Tchaikovsky: Modest Ilyich Tchaikovsky (Russian: Моде́ст Ильи́ч Чайко́вский ; 13 May [O.S. 1 May] 1850 –15 January [O.S. 2 January] 1916 ) was a Russian dramatist, opera librettist and translator.
Document 3: Miroirs: Miroirs (French for "Mirrors") is a five-movement suite for solo piano written by French composer Maurice Ravel between 1904 and 1905. First performed by Ricardo Viñes in 1906, "Miroirs" contains five movements, each dedicated to a fellow member of the French avant-garde artist group Les Apaches.
Document 4: The Mighty Handful: The Mighty Handful (Russian: Могучая кучка ), also known as The Five and The New Russian School, were five prominent 19th-century Russian composers who worked together to create a distinctly Russian classical music. Mily Balakirev (the leader), César Cui, Modest Mussorgsky, Nikolai Rimsky-Korsakov and Alexander Borodin all lived in Saint Petersburg, and collaborated from 1856 to 1870.
Document 5: Alexander Borodin: Alexander Porfiryevich Borodin (Russian: Алекса́ндр Порфи́рьевич Бороди́н ; ] , 12 November 183327 February 1887) was a Russian Romantic composer of Georgian origin, as well as a doctor and chemist. He was one of the prominent 19th century composers known as The Mighty Handful, a group dedicated to producing a uniquely Russian kind of classical music, rather than imitating earlier Western European models.
Document 6: Modest Mussorgsky: Modest Petrovich Mussorgsky (Russian: Моде́ст Петро́вич Му́соргский ; ] ; 21 March [O.S. 9 March] 1839 – 28 March [O.S. 16 March] 1881 ) was a Russian composer, one of the group known as "The Five". He was an innovator of Russian music in the romantic period. He strove to achieve a uniquely Russian musical identity, often in deliberate defiance of the established conventions of Western music.
Document 7: Trois morceaux dans le genre pathétique: Trois morceaux dans le genre pathétique Op. 15 ("Three Pieces in the Pathetic Style") is a three-movement suite for piano composed by the French composer, Charles-Valentin Alkan, published in 1837. The suite also bears the title "Souvenirs" ("Memories"). The 3 movements are "Aime-moi" ("Love Me"), "Le vent" ("The Wind"), and "Morte" ("Death").
Document 8: Visions fugitives: Visions fugitives, Op. 22, are a series of short piano pieces composed by Russian composer Sergei Prokofiev (1891–1953) between 1915 and 1917. They were premiered by Prokofiev on April 15, 1918 in Petrograd, Soviet Union. They were written individually, many for specific friends of Prokofiev's, and he originally referred to them as his "doggies" because of their "bite". In August 1917, Prokofiev played them for Russian poet Konstantin Balmont, and others, at the home of a mutual friend. Balmont was inspired to compose a sonnet on the spot, called "a magnificent improvisation" by Prokofiev who named the pieces ""Mimolyotnosti"" from these lines in Balmont's poem: ""In every fleeting vision I see worlds, Filled with the fickle play of rainbows"". A French-speaking friend at the house, Kira Nikolayevna, immediately provided a French translation for the pieces: "Visions Fugitives". Prokofiev often performed only a couple of them at a time as encores at the end of his performances.
Document 9: Pyotr Ilyich Tchaikovsky and The Five: In mid- to late-19th-century Russia, Pyotr Ilyich Tchaikovsky and a group of composers known as The Five had differing opinions as to whether should be composed following Western or native practices. Tchaikovsky wanted to write professional compositions of such quality that they would stand up to Western scrutiny and thus transcend national barriers, yet remain distinctively Russian in melody, rhythm and other compositional characteristics. The Five, made up of composers Mily Balakirev, Alexander Borodin, César Cui, Modest Mussorgsky, and Nikolai Rimsky-Korsakov, sought to produce a specifically Russian kind of art music, rather than one that imitated older European music or relied on European-style conservatory training. While Tchaikovsky himself used folk songs in some of his works, for the most part he tried to follow Western practices of composition, especially in terms of tonality and tonal progression. Also, unlike Tchaikovsky, none of The Five were academically trained in composition; in fact, their leader, Balakirev, considered academicism a threat to musical imagination. Along with critic Vladimir Stasov, who supported The Five, Balakirev attacked relentlessly both the Saint Petersburg Conservatory, from which Tchaikovsky had graduated, and its founder Anton Rubinstein, orally and in print.
Document 10: Khovanshchina: Khovanshchina (Russian: Хованщина , "Hovánščina", sometimes rendered The Khovansky Affair; since the ending -ščina is pejorative) is an opera (subtitled a 'national music drama') in five acts by Modest Mussorgsky. The work was written between 1872 and 1880 in St. Petersburg, Russia. The composer wrote the libretto based on historical sources. The opera was unfinished and unperformed when the composer died in 1881.
Document 11: Trois mouvements de Petrouchka: Trois mouvements de Petrouchka or Three Movements from Petrushka is an arrangement for piano of music from the ballet "Petrushka" by the composer Igor Stravinsky for the pianist Arthur Rubinstein.
Document 12: Mikhail Glinka: Mikhail Ivanovich Glinka (Russian: Михаи́л Ива́нович Гли́нка ; 1 June [O.S. 20 May] 1804 15 February [O.S. 3 February] 1857 ) was the first Russian composer to gain wide recognition within his own country, and is often regarded as the fountainhead of Russian classical music. Glinka's compositions were an important influence on future Russian composers, notably the members of The Five, who took Glinka's lead and produced a distinctive Russian style of music.
Document 13: The Seasons (Tchaikovsky): The Seasons, Op. 37a (also seen as Op. 37b; Russian: Времена года ; published with the French title Les Saisons), is a set of twelve short character pieces for solo piano by the Russian composer Pyotr Ilyich Tchaikovsky. Each piece is the characteristic of a different month of the year in the northern hemisphere. The work is also sometimes heard in orchestral and other arrangements by other hands. Individual excerpts have always been popular – "Troika" (November) was a favourite encore of Sergei Rachmaninoff, and "Barcarolle" (June) was enormously popular and appeared in numerous arrangements (for orchestra, violin, cello, clarinet, harmonium, guitar and even mandolin).
Document 14: Prelude in C-sharp minor (Rachmaninoff): Prelude in C-sharp minor (Russian: Прелюдия ), Op. 3, No. 2, is one of Sergei Rachmaninoff's most famous compositions. It is a ternary (ABA) prelude for piano in C-sharp minor, 62 bars long, and part of a set of five pieces entitled "Morceaux de fantaisie"; and also known as "The Bells of Moscow" since the introduction seems to reproduce the Kremlin's most solemn carillon chimes.
Document 15: Pictures at an Exhibition: Pictures at an Exhibition (Russian: Картинки с выставки – Воспоминание о Викторе Гартмане , "Kartínki s výstavki – Vospominániye o Víktore Gártmane" , "Pictures from an Exhibition – A Remembrance of Viktor Hartmann"; French: "Tableaux d'une exposition" ) is a suite of ten pieces (plus a recurring, varied Promenade) composed for the piano by Russian composer Modest Mussorgsky in 1874.
ground_truth: The Five