For more than seven decades, the opening of Milan's La Scala has been the most important opera premiere of the year, in the world's most prestigious opera house. But before the curtain rises on the first performance of Verdi's “The Force of Destiny,” more than 900 artists, choreographers, craftsmen, and stage technicians have spent months planning and rehearsing. Filmmaker Anissa Bonnefont accompanies opera director Leo Muscato and conductor Riccardo Chailly during the preparations.