Other than his friendly rival Fred Astaire, Gene Kelly was perhaps the person most synonymous with the golden age of the movie musical. Most everyone knows about “Singing in the Rain”, but one of Gene’s most technically difficult dance scenes is from another movie, “Summer Stock.” That movie almost did not happen in part because of Gene’s very famous costar. The new book “Come On, Get Happy” is about the making of “Summer Stock.” The authors are film historians David Fantle and Tom Johnson. They spoke to WFYI’s Ray Steele.