Ben Heppner is back at The Met, after more than a year of recuperation from health problems that stole his famous voice. Heppner looks great (he’s lost 60 pounds,) feels better, and this week at New York’s famous opera house he gave “a performance greeted by roars of approval from the Met audience and applause from James Levine himself, who put down his baton at one point to join in the ovation.”