Gene Kelly was originally hired as producer but left three weeks before filming. It was later suggested that he left because of disagreements with Frank Sinatra over the amount of dancing numbers in the movie.
Peter Lawford was supposed to be in this film, but due to the John F. Kennedy/Frank Sinatra falling out, Lawford - Kennedy's brother-in-law - took the brunt of the wrath from the "Chairman of the Board".
A scene depicting a kidnapping was filmed, but cut when star Frank Sinatra's son was kidnapped.
Although his name doesn't appear in the credits, the distinctive voice of the "radio announcer" heard emanating from the speaker outside the radio supply store twice during the movie belongs to Paul Frees.
Average Shot Length = ~13 seconds. Median Shot Length = ~12.3 seconds. Both values are quite high for a Hollywood film made in the mid 1960s.
In the film's trailer, dance director Jack Baker and director Gordon Douglas appear on the set of the film along with the stars.
Last theatrically released musical for Bing Crosby.
Making this film should have been fun. Instead, by more than one account, it was a waking nightmare for all involved. John F. Kennedy was assassinated soon after filming started, casting a pall over the entire set. Not long after that, Frank Sinatra Jr. was kidnapped from his dressing room at Lake Tahoe, Nevada (Upon payment of a large ransom, he was released, unharmed, a few days later). Victor Buono, who played Deputy Sherrif Alvin Potts, later observed that it was a minor miracle that filming was completed at all.
On the same day as the funeral scene was filmed, President John F. Kennedy (a personal friend of Frank Sinatra's) was assassinated.
The two lesser known Rat Packers, Joey Bishop and Peter Lawford, don't appear in this film. They are "replaced" essentially by Bing Crosby and Peter Falk.