After the outbreak of World War I, Busoni, as an Italian, found it increasingly difficult to stay in Berlin and eventually moved to neutral Zurich where he did not have to take sides.
Busoni completed the opera Turandot in double-quick time (300 pages in 100 days) in late 1916, and it was first performed with Arlecchino as a double bill - Busoni conducting - in Zurich in 1917.