In the framework of the season “Music Vaults of Belgrade” the Cultural Element and the Belgrade City Museum have prepared a unique concert “Quod Fatum” dedicated to Tchaikovsky and his friendship with Nadezhda von Meck. The anthological friendship of Nadezhda von Mech and Tchaikovsky is today one of the greatest mysteries in the life of this great composer. By exchanging over 1,200 letters between 1877 and 1890, Tchaikovsky and Nadezhda von Meck have made a significant connection, although they never met. During this time, he wrote some of the most important works: Violin Concert, Opera Eugene Onegin, Fifth and Sixth Symphony, Ballet Sleeping Beauty and Swan Lake.