The Fourth is Sibelius's most difficult symphony. For some, it is his masterpiece. When the symphony was premiered on 3 April 1911 in Helsinki, one critic compared it to Barkbröd - tree bark eaten by the Finns in times of famine! It is fittingly a Finn, conductor Santtu-Matias Rouvali, who explores this symphony that lays bare our emotions. With his Göteborg Symphony Orchestra, he continues his cycle of the complete Sibelius symphonies, with the addition of the famous Valse Triste and the symphonic poem inspired by Swedish folklore called The Wood Nymph .