Original: Jean Sibelius ( ) ( 8 December 1865 20 September 1957 ) was a Finnish composer of the later Romantic period whose music played an important role in the formation of the Finnish national identity .
Simplified: Jean Sibelius ( born Hämeenlinna ( Tavastehus ) 8 December 1865 ; died Järvenpää , 20 September 1957 ) was a Finnish composer .