Jean Sibelius, born Johan Julius Christian Sibelius) (8 December 1865 – 20 September 1957) was a Finnish composer of the later Romantic period. His music played an important role in the formation of the Finnish national identity. His mastery of the orchestra has been described as "prodigious." The core of Sibelius's oeuvre is his set of seven symphonies. Like Beethoven, Sibelius used each successive work to further develop his own personal compositional style. His works continue to be performed frequently in the concert hall and are often recorded. In addition to the symphonies, Sibelius's best-known compositions include Finlandia, the Karelia Suite, Valse triste, the Violin Concerto in D minor and The Swan of Tuonela (one of the four movements of the Lemminkäinen Suite). Other works include pieces inspired by the Finnish national epic, the Kalevala; over 100 songs for voice and piano; incidental music for 13 plays; the opera Jungfrun i tornet (The Maiden in the Tower); chamber music; piano music; Masonic ritual music and 21 separate publications of choral music. Sibelius composed prolifically until the mid-1920s. However, after completing his Seventh Symphony (1924), the incidental music to The Tempest (1926), and the tone poem Tapiola (1926), he produced no large scale works for the remaining thirty years of his life. Although he is reputed to have stopped composing, he in fact attempted to continue writing, including abortive efforts to compose an eighth symphony. He wrote some Masonic music and re-edited some earlier works during this last period of his life, and retained an active interest in new developments in music, although he did not always view modern music favorably. The Finnish 100 mark bill featured his image until it was taken out of circulation in 2002. Since 2011, Finland celebrates a Flag Day on 8 December, the composer's birthday, also known as the 'Day of Finnish Music'.