Largely critically panned on initial release, it soon became known as a midnight movie when audiences began participating with the film at the Waverly Theater in New York City in 1976. Audience members returned to the cinemas frequently and talked back to the screen and began dressing as the characters, spawning similar performance groups across the United States. At almost the same time, fans in costume at the King's Court Theater in Pittsburgh began performing alongside the film. This "shadow cast" mimed the actions on screen above and behind them, while lip-syncing their character's lines. Still in limited release forty-five years after its premiere, it is the longest-running theatrical release in film history. In many cities live amateur shadowcasts act out the film as it is being shown and heavily draw upon a tradition of audience participation. The film is most often shown close to Halloween. Today, the film has a large international cult following and has been considered by many as one of the greatest musical films of all time. It was selected for preservation in the United States National Film Registry by the Library of Congress in 2005.