The Producers (1968)

Max Bialystock and Leo Bloom, a scheming theatrical producer and his mousy accountant, hit upon the perfect plan to embezzle a fortune: raise far more money than you need to produce a sure-fire Broadway flop and then (since no one will expect anything back), Max and Leo can pocket the difference. To do this, they need the ultimate bad play, which they find in the musical Springtime for Hitler. Their plans come to naught and the duo are taken completely by surprise when their new production is hailed as a toast-of-the-town hit.