One of the bewitchments of this performance is that Pierre Boulez leaves unreconciled the two conflicting tendencies of Berg's music--on the one hand, grand Romantic opera; on the other, dodecaphony. Their clash is the hinge of Berg's exhilarating composition, and, once perceived correctly, it's a drama of almost unbearable intensity. The dense instrumental texture is brought out in stunning detail. Yes, Teresa Stratas is occasionally unsteady in the title role. But this is the King Lear of opera roles: probably unperformable and altogether unforgettable. --Joshua Cody