This 2007 production of Verdi’s La Traviata from Milan’s La Scala, with world-class singers and Lorin Maazel on the podium belongs among the best of the many fine DVD versions available. Its prime draw is soprano Angela Gheorghiu, whose 1994 Covent Garden assumption of the role of Violetta catapulted her to stardom. She doesn’t quite match the emotional power and vocal beauties...