Jean Sibelius achieved international recognition with his Second Symphony. This work, his most frequently performed symphony to this day, opens the series of orchestral works within the Complete Edition "Jean Sibelius Works. In his introduction, Kari Kilpeläinen, the author of the comprehensive source catalogue "The Jean Sibelius Musical Manuscripts at Helsinki University Library (BV 270), quotes previously unknown correspondence relating both to the origin of the Second Symphony as well as to the first performances, which triggered aesthetic controversies in Finland.