(Credit: Vincent Beaume) We are in the middle of Sesto’s aria “Parto, Parto,” mezzo-soprano Marianne Crebassa sharing  center stage with excellent clarinetist Nicola Boud, when we hear an explosion. As a long-time resident of the United States, my first thoughts were the most dreadful—gunshots, bomb, the apocalypse. Raphäel Pichon peacefully kept conducting, with longer pauses, perhaps, but, as the fear {…}