Conceived by the LA Phil for presentation at the Walt Disney Concert Hall, with a colossal overhead video from Bill Viola and discreet live action directed by Peter Sellars, this Tristan und Isolde amounts to two complementary productions in one. With a prerecorded soundtrack, Viola’s dreamscapes of the lovers amid fire and water would easily stand on their own. But living singers deserve to have a presence, too, and Sellars has served them well. Gustavo Dudamel conducts. Mary Elizabeth Williams and Gwyn Hughes Jones are heard as the adulterous lovers. —Matthew Gurewitsch