The ritual on the Green Hill dates back to 1876. That was the year Richard Wagner inaugurated the Bayreuth Festival with the premiere of Der Ring des Nibelungen, his epic “Artwork of the Future.” The world took notice, to a degree we can scarcely imagine. For the subsequent century and a half, reverent acolytes have been gathering in Wagner’s purpose-built Festspielhaus to bathe in his mysteries. And to think the hall was originally intended to serve for a single summer.

Since the Bayreuth premiere of the Master’s valedictory Parsifal, in July 1882, and his death in Venice the following winter, a single question has plagued the Wagner widows and lineal descendants in charge of the festival. What do you do when the shock of the new wears off and you’ve become a fixture? Phase one, consolidate the approved repertory. Phase two, cultivate superstars. Phase three (post-Holocaust), de-Nazify. Phase four (starting with the centennial, in 1976), empower game-changing directors, crackpots welcome.