For female lead Kathy Selden, such stars as Judy Garland and June Allyson were considered, but Kelly was sold on starlet Reynolds. She was a gymnast who’d been discovered in a beauty pageant and landed a couple of small movie roles. She was also still a teenager, but Kelly was certain she had the athleticism and vocal chops the part required.
Reynolds, however, wasn’t so sure. She had no dance training, and she found co-director/choreographer/co-star Kelly a tyrannical taskmaster. One day, she was so despondent that she curled up beneath a piano and started to cry – only to be found by Fred Astaire, who gave her some dance coaching. By the time she filmed the “Good Morning” number, she was able to keep up with Kelly and O'Connor, but after the 14-hour shot was done, she had to be carried to her dressing room because her feet were bleeding.
Years later, she would praise Kelly as the most exciting director she’d ever worked with, while he called her “strong as an ox” and complimented her on her ability to learn complicated routines quickly. Still, she said, “The two hardest things I ever did in my life are childbirth and "Singin’ in the Rain’.” [x]