As if the official title weren’t enough of a mouthful, cognoscenti refer to this bewildering but hypnotic mystery play of an opera as “the Russian Parsifal.” A generation ago, when Valery Gergiev’s wholesale colonization of the West by the Mariinsky Theatre was just beginning, an antique, traditional Kitezh was one of the principal treasures on offer. These days, the company performs a revisionist makeover by the ever-controversial Dmitri Tcherniakov, but it’s still Gergiev on the podium, without peer in this music. —M.G.