Thanks to conductor William Christie's ensemble Les Arts Florissants, the operas of the French Baroque era have made a major resurgence back into the international repertoire, and the group's near-annual appearances in New York are awaited like no other early music ensemble today. Tune in to this week's Saturday Night At The Opera to hear the performance that instantly took the opera world by storm, Jean-Baptiste Lully's Atys. Les Arts Florissants's initial production, which deftly blended the stylized costumes and dances of Louis XIV's court with contemporary naturalism, first premiered in 1986, yet its rapturous reception has led to major revivals around the world, most recently in an entirely sold-out run at the Brooklyn Academy of Music in 2011. Stepan Atamian hosts.