Soprano Nadine Sierra stars as the self-sacrificing courtesan Violetta—one of opera’s ultimate heroines—in Michael Mayer’s vibrant production of Verdi’s beloved tragedy. Tenor Stephen Costello is her self-centered lover, Alfredo, alongside baritone Luca Salsi as his disapproving father, and Maestro Daniele Callegari on the podium. Three hours, 15 minutes.