"We wanted Lina Lamont to be a combination of Mae Murray and Judy Holliday in Born Yesterday", Gene Kelly explained to his biographer Clive Hirschhorn, "and as Jean had played in Born Yesterday on the road, we tested her and she was just perfect".
The casting of Debbie Reynolds proved to be more controversial. She was then an inexperienced performer who would struggle during exhausting rehearsals to keep up to Kelly's impressive dancing technique. In 1962 (TV Radio Mirror) Reynolds had declared: "Gene would come to see what progress I was making. I couldn't dance a step, he'd just smile and say 'we'll have to work a little harder', he had me on sound stages day after day, studying modern dancing with Carol Haney and Jeanne Coyne and tap & ballet with Ernie Platt... I owe more to him than I can ever repay. He literally willed me to dance". In 1998 she reiterated her feelings: "Gene taught me how to work beyond all reason. He wouldn't let me leave until I was letter-perfect". No doubt Kelly was a noted perfectionist admitted by himself: "I've always tried to reach for perfection, knowing that I could never achieve it".
Although Reynolds had said Louis B. Mayer imposed her against Kelly's protests, in sharp contrast to her story, Gene Kelly claimed in an interview for Tom Johnson & David Fantle in 1994: "That is patently untrue. Mayer wasn't even at the studio in 1952 when we shot the picture." In the early 1970's Kelly had assured Hirschhorn that "no one else at the studio could have touched it. I insisted she be used, and never had any meeting with Mayer concerning Singin' in the Rain.
The most memorable dance sequences in the film were the title number Singin' in the Rain (a delightfully wet solo performance by a literally feverish Kelly, that will go on burning our enraptured hearts): "I kiss this girl good night, and I'm so in love I don't care if it's raining, I put my umbrella down and act like a eight-year-old kid, sloshing through puddles and being happy" (Gene Kelly explained to Graham Fuller), "Broadway Rhythm Ballet" with Cyd Charisse, "Moses Supposes": "Donald and I rehearsed that dance for days, but most critics dismiss it as a zany Marx Brothers romp," "Good Morning", and the hysterical "Make 'em Laugh" (a brilliant Donald O'Connor's slapstick tour-de-force).
Gene Kelly made changes in the script, creating a slightly satirical portrayal of Hollywood's sound transition. The same furniture from Flesh and the Devil (starring John Gilbert and Greta Garbo in 1927) appeared in Don Lockwood's home set, and exact replicas of the Cooper-Hewitt lights were shown. Rita Moreno playing Zelda Zanders, Lina's informant friend, is probably inspired on Clara Bow. Also, the protagonist Don Lockwood had similarities with the real Gene Kelly (his career in MGM, his ascension to the Hollywood firmament, his stern self-confidence and his romantic nature - he'd proposed his first wife Betsy at the fountain of the Plaza Hotel, then whisked her off to Hollywood when he was signed by David O. Selznick).