Mel Brooks wanted to make a movie about how two producers schemed to make a killing on a sure-flop musical entitled, Springtime for Hitler. The problem was that no one wanted to finance a movie titled, Springtime for Hitler.
After several years of begging, Sidney Glazier agreed to produce it and the money was put up by Joseph Levine, a producer with an international reputation. Like many movies that end up being classics, The Producers was made by people who ended up hating each other (well, except for Gene Wilder, of course). It was a very unhappy eight week shoot in NYC. Then came months of editing. Finally, it was released, sort of. It opened in a small theatre in suburban Philadelphia (Glazier's hometown) where I saw it. There were not a lot of people in the theatre and no one was laughing except for me and a friend who had seen it the night before and dragged me to it the next night.
Then, it was released in New York. Most of the critics didn't get it - they criticized the movie for being about a musical based on the life of Hitler. One critic wondered if they were going to do a musical about cancer next. In spite of the mixed reviews, the movie made money in NYC but was, generally, a flop. The fact that the producers in the movie wanted to produce a sure fire disaster musical as part of their scheme to steal millions and that is why they produced a musical about Hitler was overlooked. A musical about Hitler? This was blasphemy!