“Symphonies are attempting to lure these 22-to-37-year-olds with drastically increased social media presences, discounted tickets, and exclusive backstage access. Opera companies are capitalizing on the socializing aspect of their milieu and setting snares of free hors d’oeuvres and drinks during intermissions.” Jeremy Reynolds looks at the programs of the San Francisco and Atlanta Symphonies, the Cleveland Orchestra, and Houston Grand Opera.