Das schlaue Füchslein
- he started a number of great friendships, for example with Leoš Janáček, whom he made the world premiere of his opera "Káťa Kabanová" (November 23, 1921) and later his other operas, too ("Liška Bystrouška" – "The Cunning Little Vixen", "Její pastorkyňa" – "Her Stepdaughter")