Elvis made this film in a deal with the floundering Allied Artists which saw him take a pay cut and not record any new material in exchange for 50% of the film's profits. The film was a big earner, which is credited in saving Allied Artists from bankruptcy.
This is the only movie for which Elvis Presley did not record a new soundtrack. All the songs had been recorded between 1960 and 1963, and had already been released on several albums or singles.
While filming Elvis Presley gave his Sony video camera to director Norman Taurog. At the time those cameras were really rare in USA. Taurog liked the idea of it because with video camera he can shoot the scene himself and watch the scene before it goes to edit.