Jean Sibelius (born Johan Julius Christian Sibelius) was a Finnish composer of the late Romantic period, whose music played an important role in the formation of a Finnish national identity. The core of his ouvre is his set of seven symphonies, which reflect the development of his compositional style. In addition to those, his best known compositions include the symphonic poem Finlandia, the Karelia Suite, the Valse Triste, the Violin Concerto in D minor, and The Swan of Tuonela. His output includes nationalistic pieces, incidental music, songs, an opera, and choral music. After 1926, Sibelius ceased to work on large scale pieces: having paid off his debts and secured a state pension, he retired and lived a quiet life. He retained an active interest in new developments in music. He was also a freemason (and he wrote a number of pieces to be used in Lodge ritual). Currently Finland celebrates 8 December, the composer's birthday, as the 'Day of Finnish Music'.