Profiling Gene Kelly (1912-96), who revolutionized movie musicals in the 1940s and early '50s with his athleticism and Everyman style, and splashed his way to immortality in “Singin' in the Rain.” This biography features clips from the high points of Kelly's career (“Cover Girl,” “On the Town,” “An American in Paris” and, of course, “Rain”), and emphasizes his painstaking work ethic. Says Debbie Reynolds: “The two hardest things I ever did in my life were childbirth and 'Singin' in the Rain'.”