Dudley Moore, who plays an orchestra conductor, shadowed Bill Conti, who wrote the film's score, to actually learn the techniques used to conduct a symphony orchestra.
The classical piece of music that Dudley Moore acts out his revenge fantasy to was Pyotr Ilyich Tchaikovsky's violin concerto.
In the original poster art and on the DVD cover Kinski wears a glamorous red-sequined cocktail dress that never appears in the finished film.
Comedy star Dudley Moore, who plays the piano in this film, in real life was an accomplished pianist.