In the "Singin' in the Rain" finale, Buster Keaton is shown carrying a small package in his left hand. This visual gag is a reference to Uneeda Biscuits, then a popular product made by Nabisco. The Uneeda Biscuit trademark showed a small boy wearing a yellow rain slicker and hat (similar to the outfits that the cast is wearing in this number) and walking home in the rain with a package of Uneeda Biscuits under his arm.
Lon Chaney had just signed a new three picture a year deal with MGM when he was asked to do a cameo in the all-star film. Chaney agreed if it would count as one of his three contracted pictures and he would be paid his regular fee for the bit. As his salary would have eaten up most of the film's budget, the part was played by Gus Edwards with a mask and costume from London After Midnight (1927). Chaney was not happy that his name was exploited with the song, "Lon Chaney Will Get You if You Don't Watch Out." When he died in 1930, the sequence was deleted from existing prints out of respect but was later restored.
The version shown on Turner Classic Movies is a sound-on-disc print, with the left side of the screen noticeably cropped off in order to accommodate a sound-on-film track, with the result that the title credits and all the ensembles appear to be photographed off center, which was not the case when the film was theatrically exhibited.
The balcony scene from "Romeo and Juliet" provides the only Technicolor footage in the careers of either Norma Shearer or John Gilbert, as all of their other movies were filmed in black-and-white.
Film historians have long assumed that there is missing or lost footage from this film based on its copyright length, which was listed at 130 minutes, while all surviving prints run 118 minutes. However, the copyright length appears to have been registered in error, as the running order of skits and musical numbers in the existent 118-minute version is exactly the same as the listed running order that appears in the original 1929 souvenir program that accompanied first run exhibitions of the film. This clearly indicates that no footage is missing, and that the film's true running time is, and always has been, 118 minutes.