Johnny Fontane from The Godfather and Frank Sinatra have very similar personalities based on the movie. Many people believe that it is the symbolic representation of Sinatra. Ever since the movie came out many people have shifted their opinion on Sinatra and think less highly of him.
Little known fact: Vic Damone was almost Johnny Fontane. The popular singer was originally cast as Johnny Fontane. He dropped out, attributing his pride in being Italian, though he would later state that it was all about the money.