Being a member of the court requires much preparation, usually months ahead. Women and girls must have dress fittings as early as the May before the parade, as the season of social balls allows little time between each parade. These balls are generally by invitation only. Balls are held at a variety of venues in the city, large and small, depending on the size and budget of the organization. In the late 19th and early 20th century, the French Opera House was a leading venue for New Orleans balls. From the mid 20th century until Hurricane Katrina the Municipal Auditorim was the city's most famous site for Carnival balls. In more recent years, most are at the ballrooms of various hotels throughout the city. The largest "Super Krewes" use larger venues; Bacchus the Morial Convention Center and Endymion the Superdome.