Glimmerglass Plans 4 Shows On Lawn Opera will be back on Otsego Lake’s shores this summer. The Glimmerglass Festival announced today it will build an outdoor stage on the festival grounds, where it will present four operas. The 2021 season will run July 15 through Aug. 17 with performances of Mozart’s “The Magic Flute,” Verdi’s “Il Trovatore,” Offenbach’s “Songbird” (La Périchole), and the world premiere of “The Passion of Mary Cardwell Dawson,” a new play with music about the founder…