The Paris Opera is doing a radical rethink of Wagner’sTristan und Isolde. The company has commissioned video artist Bill Viola to accompany its new production. “On a 30-foot-wide screen above and behind the somberly lighted space peopled by the singers, images that recall some of Mr. Viola’s well-known video pieces variously offer literal, metaphorical and even spiritual complements to one of mythology’s most famous and tragic love stories. With only the preludes played to a closed curtain, Mr. Viola’s multi-toned video poem runs for some 3 hours 40 minutes, a full-length spectacle in its own right.”