A caricatured Django Reinhardt playing guitar can be seen early in the black and white portion of the film. As in reality, the cartoon uses only two fingers to play, due to a burn suffered in 1928. Eventually, he brings his foot up and plays with his toes. The film's soundtrack sounds as though it was greatly influenced by Django's music (and he recorded a song called Belleville with Stéphane Grappelli).
There is also an animated caricature of dancer/singer/performer Josephine Baker, a black American entertainer who left the U.S. in the 1920s to escape its virulent racism, and became a tremendous star in Europe. She was very famous in Paris, and often appeared in shows half-nude, the way she's represented in this film.
In the beginning of the movie, when they're watching TV, there's an equation in the bottom of the screen. These are Albert Einstein's Field Equations and represent the gravitational effects produced by a given mass.
"Roberte Rivette", the accordionist who plays her instrument atop a truck while following the cyclists in the Tour de France, represents Yvette Horner, the mega-selling artist who still records albums and plays her accordion to large crowds in France. Horner recently described her own exfperiences as very similar to those of "Roberte Rivette" in "Les Triplettes de Belleville": she continued playing her accordeon along the Tour de France route with a big smile as insects ceaselessly were caught in her teeth.
The yellow-jerseyed leader of the Tour de France depicted in the film is a caricature of five-time tour winner Jacques Anquetil. It would appear that the year is 1957, the year of Anquetil's first win and the only year he participated which featured a stage finish in Marseilles.
The pianist Mme. Souza and young Champion are watching on television is a caricature of the famous Canadian virtuoso, Glenn Gould, known for his piano interpretations of Johann Sebastian Bach's keyboard works and for the fact that he would hum along as he played the piano (which can be heard in the film).
The president seen giving an official television address, asking his fellow citizens to cheer on the cyclist, is French statesman Charles de Gaulle (1890-1970), reinforcing the idea that this movie is set in the 1950s.
The song heard in the background of the barbershop sequence (listed as the "Barber Song" in the closing credits) has lyrics in Italian, which are actually complete non-sequitur gibberish referring to food, clothing, Federico Fellini movies and other words that a non-speaker of Italian would find difficult to follow.
The bicycles are all computer generated and traced, because the director, Sylvain Chomet, did not believe it was worth the time to get the look of the bicycles "perfect". The figures on the bicycles, however, were only thin lines in the computer generated originals, allowing the animators to breathe life into them.
The equation which features on an opening screen, R(uv) - 1/2 g(uv)R = - 8 pi GT(uv), is similar to ones used in unimodular relativity and cosmological constant equations (where the "uv"s in parentheses are subscripts).