Jakub Hrůša, the Royal Opera’s music director, joins with the director Evgeny Titov in his company debut for a “bold, dreamlike, and disturbing” new production of Richard Wagner’s churchy but highly narcotic valedictory from the stage and the world. Temperamentally and in appearance, the French tenor Stanislas de Barbeyrac might have been born to enact the eponymous Holy Fool, whose trajectory leads from cluelessness to compassion so great as to redeem the world. The incisive British bass Brindley Sherratt sings Gurnemanz, veteran knight of the Holy Grail who knows where all the skeletons are buried and narrates the back story in exhaustive detail. In the baritone part of Amfortas, the agonized king of the Grail’s collapsing confraternity, there’s the German lieder specialist Christian Gerhaher, prone to affectation. The Russian mezzo-soprano Ekaterina Gubanova, whose undimmed artistry compensates for paling vocal resources, assays Kundry, the time-traveler who is part Lilith, part Mary Magdalene. —Matthew Gurewitsch