If it weren’t for the persistent notion that ballet depends on story and stunt, most 19th-century works would never have survived their own century, much less persevered into ours. But Giselle has earned its longevity. While blockbusters such as Le Corsaire and La Bayadère have needed total makeovers to pass go, Giselle remains supernaturally affecting and vividly revolutionary after all these years—no revision necessary. This season features two vibrantly faithful productions. The Royal Ballet’s longstanding Peter Wright version has roots in the French original by way of Imperial Russia. The six-week London run fields Giselles both veteran (Osipova, Nuñez, Hayward, Lamb) and neophyte (O’Sullivan, Kaneko). The Royal Danish Ballet may be a relative newcomer to Giselle, but its age-old commitment to founding choreographer Auguste Bournonville, a Giselle contemporary, guarantees folkish allegro, fine acting up and down the ranks, and the right spirit. In earth and jewel tones, Mia Stensgaard’s elegantly streamlined costumes and Maja Ziska’s evocative scenography enhance the ballet’s ever-shifting mood. —Apollinaire Scherr