The State Opera South Australia is set to present “G&S FEST,” a 10-day-long celebration of the work of W.S. Gilbert and Arthur Sullivan. Marking International Gilbert & Sullivan Day (May 3) the State Opera South Australia will put on full productions of “Trial by Jury,” “H.M.S. Pinafore,” “Pirates of Penzance,” and “The Sorcerer.” Other celebratory events include a G&S-themed high {…}