Municipal Musicals will stage its fifth production, “The Merry Wid ow,” on May 16, 17 and 18 in the Student Union Auditorium. “On the basis of first-week tick et sales, ‘The Merry Widow’ will surpass even ‘Brigadoon’ at the box office,” according to Robert Wallace, ticket manager. “Sales for opening night are especially heavy,” Wallace reported. “And this marks an interesting shift in public acceptance. Previ ously, people seemed to wait for reports from their friends before they decided to buy tickets with the result that Thursday and Fri day nights saw the largest audi ences. It looks like folks have faith now that if it’s a Municipal Musicals show, it’s bound to be good.” Municipal Musicals shows have always been staged with a lavish hand. It is reported, however, that “The Merry Widow” will outdo all the others. Considerable secrecy surrounds the “living portrait” scene in which five huge paintings being executed by Dick Broyles for the Mozovian Embassy set sud denly come alive. Beyond admit ting that “it’s all done with lights not mirrors,” Municipal Musi cals directors are mum on the subject. Rumor has it too that some in teresting effects are planned with five larger-than-life statues being sculptured by Bette Ruozella, Jim Frye and Wayne Bowman. The statues will grace the Maxim's Cafe scene. But the two features that have made “The Merry Widow” the most popular show in the history of the musical theater are not the elaborate scenic effects nor the spectacular costumes. Glorious music and side-splitting comedy are the two ingredients that have kept audiences in every civilized country in the world enthralled for almost 50 years. Tickets for “The Merry Widow” are on sale in the lobby of the Terre Haute House.