As Stephen Schwartz prepares for the local premiere of his first opera, Séance on a Wet Afternoon, he sits for a panel discussion on the set of his other New York hit, Wicked. Joining him are singer and songwriter Rufus Wainwright, librettist David Henry Hwang, Adam Guttell[Guettel? Add an E and remove an L?] (The Light in the Piazza) and John Kander (Cabaret and Chicago) in a discussion of what distinguishes opera from musical theater. City Opera general manager George Steel will moderate the conversation.