If you've ever been watching a movie when a sudden plot twist left you feeling you're watching an entirely different film, you may have been the victim of a movie that totally changed genre. While there are many movies that took hard left turns, most of the movies that have totally different second halves use the twist for a good reason.
When The Sound of Music switches from feel-good musical to escaping-from-evil-suspense, the audience roots for the protagonists since we've developed a relationship with them. And when Titanic shifts from love story to action film, the romance between Jack and Rose has been set up enough that viewers aren't sunk along with the ship.
But not all movies are able to shift tone or genre so easily and many movies that shifted tones partway through lost their audience's attention as well as any understanding of the film's story. So, what makes some movies that made dramatic tonal changes work and others not? It depends how the first part of the movie is set up, as well as how different the two halves of the film really are. Here are the best examples of films that left viewers spinning after a dramatic story shift.