Dame Joan’s final Seattle appearance came in Massenet’s Le roi de Lahore, a rarity unearthed by conductor Richard Bonynge as a vehicle for his wife’s dazzling voice. Le roi struck many Seattleites as highly peculiar, particularly the scene in Act II when the King ascends to heaven accompanied by an East-West harem ballet (as he lies bleeding on the celestial stairway), and the chorus, swathed from top to toe in fabric, sang what sounded like “Climb Ev’ry Mountain” in French. But it would take more than a haphazard plot to derail Dame Joan in superb voice and full cry. At 50, she could convincingly fool the ear, if not the eye, as a 19-year-old virgin priestess. Her fabled soprano soared to a high D-flat with “the kind of authority that makes the chandeliers wobble,” and the house rang with “Bravas.”