Bart identified himself to his friends in the European underground by whistling the melody from the French song "Frêre Jacques."

TRIVIA NOTE: The 1954 mystery series THE WHISTLER syndicated by CBS Films used an eerie 13 note whistle performed by Dorothy Roberts to set the mood for the program. The Whistler was played by Bill Forman "who knows many things for he walks at night!" The series ran 39 episodes and was based on the famous radio series which aired on CBS radio from 1942-1954.

Novelist Leslie Charteris' character Simon Templar, a sophisticated wealthy playboy/crook whistled the melody "Da Dee Dee Dee Dee Dee Dee Da" to announce his presence in a number Saint films starring George Sanders in the 1940s. The Saint's melancholy tune was composed by Leslie Charteris. Of course, the origin of the whistle is in contention.

Some sources say the famous eight-note tune was composed by a Roy Webb while others say the tune originated with the Charteris family who used the whistling melody to announce their arrival home. [The Internet Movie Data Base lists Roy Webb as "uncredited" for the music in the early Saint films but attributes the theme song melody to Leslie Charteris in the 1962 Saint series with Roger Moore.]

The situation comedy THE ANDY GRIFFITH SHOW/CBS/1960-68 begins with a folksy theme song whistled by composer Earle Hagen. Some people have erroneously attributed the whistling to Fred Lowery a renowned blind whistler who penned an autobiography called "Whistling in the Dark."

The movie The Bridge Over the River Kwai (1957) also features a melodic whistle "Dee Da Da Da Da Dee Dee Da") performed by Allied soldiers held captive by the Japanese in the 1940s.