“Silent Night,” Puts’ first opera, received its premiere at Minnesota opera in 2011 and won a Pulitzer Prize the following year. According to its libretto, during a late December in World War I, French, German and Scottish troops found it possible to declare an unofficial “truce” and celebrate a common holiday in brotherhood. This story has been told in several other artistic formats including the French film “Joyeux Noël” on which Campbell based his libretto.