You think Wagner’s “Ring” is long? Karlheinz Stockhausen’s Licht (composed over the years from 1977 to 2003) consists of seven operas, named for the seven days of the week. The music alone clocks in at 29 hours. Often called the Father of Electronic Music, Stockhausen spirals around Eve, Lucifer, and the archangel Michael. Noh drama is said to have been a major influence—also The Urantia Book, a crackpot tome first published in 1955, supposedly the work of a celestial hand (or hands.) The challenges of Licht being what they are, even fragmentary performances are rare in the extreme. A 15-hour digest at the Holland Festival in 2019 appears to be the most complete to date. Pierre Audi, who masterminded that lollapalooza, has now assembled shards from several but not all the “days” of Licht in two programs for the Park Avenue Armory. There’s the option of a six-and-a-half-hour marathon that includes two intermissions and a one-hour dinner break. Heck, that’s on a par with Götterdämmerung. —Matthew Gurewitsch