A first! To mark the opening of its 2019–2020 season, the Staatskapelle Berlin and the Staatsoper Chorus, the ensemble singers and behind-the-scenes staff (costume, make-up, tech, and more), welcome visitors young and old, newcomers and regulars, for a festive day full of music. Take your kids backstage—they want you to!—and hook them on the opera house for life. Free. —L.J.