The composer Bernard Herrmann collaborated with Alfred Hitchcock on most of his great movies. If you watch dialogless scenes from these movies with the sound off (e.g. take any thriller scene from Psycho), you’ll see just how important Herrmann’s contribution was. It often seems as if Hitch was just roughing out the video, trusting Herrmann’s audio to make it work.
Like many another composer, Herrmann could not resist writing an opera, for which he used the book Wuthering Heights. Now I think it would have been really neat if Herrmann had gone to Hitchcock and said, “Look, I’m going to write an opera. How about giving me a plot?” I’ll bet Alfred Hitchcock would have loved to plot an opera.