Question: When was the Piano Concerto composed?
Context: Ludwig van Beethoven's Rondo for piano and orchestra in B-flat major, WoO, 6 was composed in 1793 and originally intended as the final movement for his second piano concerto.  Hans-Werner Küthen states this was probably the finale for the first and second versions of the second piano concerto, being replaced by the final version of the rondo in 1795.  He also notes that the most likely inspiration for the insertion of an andante section into the rondo is the concluding rondo of Mozart's twenty-second piano concerto. The compositions of Sergei Rachmaninoff (1873–1943) cover a variety of musical forms and genres.  Born in Russia, he studied at the Moscow Conservatory with Nikolai Zverev and Anton Arensky, and while there, composed some of his most famous works, including the first piano concerto (Op. 1) and the Prelude in C-sharp minor (Op. 3, No. 2).  Although spread over three different opuses, he did go on to complete an important set of 24 preludes in all the major and minor keys.  His Symphony No. 1 (Op. 13) was one of his first compositions as a "Free Artist" after graduation, and subsequently his first critical failure.  The derision he received sent him into depression.  After being sent through autosuggestive therapy, he composed his second piano concerto (Op. 18), which is still part of the major orchestra repertoire today.  In 1909, he made his first tour of the United States, and composed Piano Concerto No. 3 (Op. 30), notable for its difficult cadenza.  After this, due to migration from Russia in 1917 and his busy concert career, his output as a composer decreased, and during this period, he completed only six compositions.  His last work, "Symphonic Dances" (Op. 45), was completed in 1940. Sergei Vasilievich Rachmaninoff (Russian: Серге́й Васи́льевич Рахма́нинов , "Sergey Vasilyevich Rakhmaninov"; ] ; 1 April [O.S. 20 March] 1873 28 March 1943) was a Russian virtuoso pianist, composer, and conductor of the late-Romantic period, some of whose works are among the most popular in the romantic repertoire. The Piano Concerto No. 2 in F minor, Op.  21, is a piano concerto composed by Frédéric Chopin in 1829.  Chopin wrote the piece before he had finished his formal education, at around 20 years of age.  It was first performed on 17 March 1830, in Warsaw, Poland, with the composer as soloist.  It was the second of his piano concertos to be published (after the Piano Concerto No. 1), and so was designated as "No. 2", even though it was written first. The Piano Concerto No. 3 in A-flat major is the piano concerto composed by Japanese composer Hisato Ohzawa.  This work is subtitled Kamikaze after the aircraft Kamikaze, and was premiered by the baton of the composer on June 6, 1938, a month after the work was completed. The Yellow River Piano Concerto () is a piano concerto arranged by a collaboration between musicians including Yin Chengzong and Chu Wanghua, and based on the "Yellow River Cantata" by composer Xian Xinghai.  Since its politicised premiere in 1969 during the Cultural Revolution, the Concerto has become popular in China and amongst overseas Chinese nationalists.  It is noted for a difficult solo part.  This piano concerto and the Butterfly Lovers' Violin Concerto, which tells the story of the Butterfly Lovers, are two internationally known Chinese works that combine Western music methodology with Chinese source materials. The Piano Concerto is the only piano concerto composed by the Japanese composer Akio Yashiro.  The work was composed between 1964 and 1966 from a commission by NHK for National Art Performance of Ministry of Education, Science and Culture of Japan.  He won 16th Otaka prize with this concerto.  On July 10 and 11, 1967, the work was recorded for its premier broadcasting at NHK broadcasting centre and the recording was on air on November 5.  This premier recording was performed by pianist Hiroko Nakamura accompanied by NHK Symphony Orchestra conducted by Hiroshi Wakasugi.  The first public performance was on November 29, 3 weeks later from broadcasting, at the extra concert of NHK symphony orchestra with conductor Tadashi Mori and the same pianist. The Piano Concerto in B-flat, Op. 58, F.108, was written by Arthur Bliss in 1938 and premiered in 1939.  It is a powerful work in the nineteenth-century Romantic tradition, and at the time it was hoped it could prove to be a British "Emperor" concerto.  Nicolas Slonimsky described it as "Lisztomorphic in its sonorous virtuosity, Chopinoid in its chromatic lyricism, and Rachmaninovistic in its chordal expansiveness". The Piano Concerto No. 24 in C minor, K.  491, is a concerto composed by Wolfgang Amadeus Mozart for keyboard (usually a piano or fortepiano) and orchestra.  Mozart composed the concerto in the winter of 1785–1786, finishing it on 24 March 1786, three weeks after the completion of the Piano Concerto in A major.  As Mozart intended to perform the work himself, the soloist's part was not fully written down.  The premiere was in early April 1786 at the Burgtheater in Vienna.  Chronologically the work is the twentieth of Mozart's 23 original piano concertos. Mariela Cingo (born 14 February 1978 in Korçë, Albania) is an Albanian pianist currently residing in the United Kingdom.  She started to learn music from the age of 6, and gave her first concert at the age of 7.  By the time she was 12, she had played the Haydn Piano Concerto in D with the Korcë Philharmonic Orchestra.  At the age of 17 she moved to the UK to continue her studies under the tuition of Professor Raphael Terroni at the London College of Music.  There she won many prizes, including the Piano Concerto Prize for her performance of Rachmaninoff's Second Piano Concerto.  Her recent engagements have included performances of Rachmaninoff's Second Piano Concerto with the Sutton Symphony Orchestra and Schostakovich's Second Piano Concert with the Orchestra of the London College of Music.
Answer: late-Romantic period