'Sonntag,' by Karlheinz Stockhausen, in Cologne

The quasi-Christian mix of science and religion in "The Urantia Book" — the text Stockhausen bought from the wizardly figure — became the spiritual basis for a huge operatic cycle, "Licht" ("Light"). Written from 1977 to 2003, "Licht" exceeds even Wagner's "Ring" cycle in its epic proportions, comprising seven full operas, one for each day of the week, and clocking in at 29 hours total. Stockhausen died in 2007, without having seen "Licht" staged in its entirety. But his work has found new life at the Cologne Opera, which in recent weeks presented the culmination of the cycle, "Sonntag" ("Sunday"). To house the production the company built two theaters within the cavernous Staatenhaus am Rheinpark, part of the city's exhibition center.