Here’s a tip from the Patrick G. and Shirley W. Ryan Opera Center’s April 4 “Rising Stars” concert, an end-of-season talent show featuring members of the Lyric Opera‘s elite training program: Amber Wagner. It’s great if a diva has a charismatic stage presence (like the center’s Broadway-worthy Angela Mannino), and can slip into a glamorous little black dress–but in the end, it’s the sound that counts. When Wagner’s soprano voice is raised, nothing else matters. Lucky for us, she’ll be back next year. In the meantime, as a 2007 winner of the Metropolitan Opera’s national auditions, she’s she can be seen in a Met documentary, The Audition, that will be shown April 19 at the same Chicago and suburban movie theaters that have been running the Met’s HD broadcasts.