Director and choreographer Mark Morris’s production of Gluck’s masterpiece updates the immortal story from its ancient Greek roots to the timeless present, where, he says, “the union of chorus and dancers feels inevitable and inseparable.” With costumes by Isaac Mizrahi and a set designed by Allen Moyer, this production surrounds the action with the superb Met chorus dressed as a crowd of historic characters who bear witness to the transformative power of love. Orfeo (Stephanie Blythe) is so consumed with grief at the death of his beloved Euridice (Danielle de Niese) that the gods (Heidi Grant Murphy as Amor) allow him to lead her back from the underworld—if he will not look at her on the way. Of course he can’t resist looking, but the gods are truly merciful.