Question: The pieces Pictures at an Exhibition are composed by a Russian composer who belonged to this group known as what?

Context paragraphs:
Alexander Serov: Alexander Nikolayevich Serov (Russian: Алекса́ндр Никола́евич Серо́в , Saint Petersburg, 23 January [O.S. 11 January] 1820 – Saint Petersburg, 1 February [O.S. 20 January] 1871 ) was a Russian composer and music critic.  He is notable as one of the most important music critics in Russia during the 1850s and 1860s and as the most significant Russian composer in the period between Dargomyzhsky's "Rusalka" and the works of Rimsky-Korsakov, Mussorgsky, and Tchaikovsky.

Pyotr Ilyich Tchaikovsky: 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.

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.

Dmitri Capyrin: Dmitri Yuryevich Capyrin (born 1960 in Moscow) is a Russian composer of contemporary classical music.  He graduated from Lviv Conservatory in 1984.  He lives in Moscow and works as a freelance composer.  His music "successfully combines a variety [of] techniques, often using literary sources and motifs in his works."  He won the second prize in the 1994 ICONS competition in Turin and received a scholarship in 1995 from the Berlin Akademie der Künst.  In 2010 he was the finalist of the YouTube Online Composers Competition.  His compositions have been performed by "numerous prominent ensembles and soloists, and has also been featured in a variety of concert and festival venues, including the Moscow Autumn (1999), the Paris Presences (1993), Warsaw Autumn (2005) and the Music Biennale Zagreb (1993, 2011)."  He has become "one of the most prominent composers of the younger generation of Russians."  His style combines modal scales procedures with new tonal and atonal idioms.  He prefers polyphonic texture and dense stratification of flexible melodic voices.  At the same time he widely uses isolated tones and brief solo phrases surrounded with silence which resembles quasi-Webernian pointillism.  His work list includes pieces of various genres from opera, symphonies and one movement poems for full and chamber orchestras, concertos for harp and oboe with orchestra, pieces for various chamber ensembles, duo and solo works.  Among the performers of his music there are Yvar Mikhashoff, Claude Delangle, Marc Sieffert, Valery Popov, Moscow Contemporary Music Ensemble, Russian National Orchestra, National Academic Symphonic Band of Ukraine, Kyiv Sinfonietta, Da Capo Chamber Players.

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.

Pictures at an Exhibition (disambiguation): Pictures at an Exhibition is a suite of ten piano pieces composed by Modest Mussorgsky.

Morceaux de salon (Rachmaninoff): Morceaux de salon (French for "Salon Pieces"; Russian: Салонные Пьесы , "Salonnyye Pyesy"), Op.  10, is a set of solo piano pieces composed by Russian composer Sergei Rachmaninoff in 1894.

Alexander Radvilovich: Alexander Yuryevich Radvilovich (Russian: Александр Юрьевич Радвилович ; born 1955) is a Russian composer, pianist and teacher from Leningrad (now Saint Petersburg) from which Conservatory he also graduated at which he was under guidance from Sergei Slonimsky.  In 1992 and 1994 respectively he was the first ever composer of Russian origin to get education at the International New Music in Darmstadt.  He is known for his symphonies of two of his own poems called "Legend About Violinist" and "Pushkin".  At one time, after reading Fyodor Dostoyevsky he composed a string quartet called "The Boy at Christ’s New Year Celebration" and also designed a mini opera called "Let’s Write Fairy-tale".  He also composed an opera called "Hindrance" which was based on Danii Kharms' poem "Ruin of the Gods".  Currently he is a member of both Russian Composer’s and Saint Petersburg Composer's Unions and works as music pedagogue at the Humanitarian University of the Petersburg Conservatory.  On occasion, he tours the world as composer, pianist and leader of the Sound Ways which he also founded back in 1989.  His music is published by various labels in countries such as Russia, the Netherlands and the United States.

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.

Symphony No. 2 (Rachmaninoff): Symphony No. 2 in E minor, Op. 27 is a symphony by the Russian composer Sergei Rachmaninoff, written in 1906–07.  The premiere was conducted by the composer himself in Saint Petersburg on 8 February 1908.  Its duration is approximately 60 minutes when performed uncut; cut performances can be as short as 35 minutes.  The score is dedicated to Sergei Taneyev, a Russian composer, teacher, theorist, author, and pupil of Pyotr Ilyich Tchaikovsky.  Alongside his Piano Concerto No. 2 and Piano Concerto No. 3, this symphony remains one of the composer's best known compositions.

Supporting paragraphs: Pictures at an Exhibition (disambiguation) Modest Mussorgsky
Answer: The Five