Although uncredited, Gwen Verdon was assistant choreographer in the film version of Sweet Charity (1969).
Shirley MacLaine was working with a painful infected tooth that required root canal treatment, yet she was such a trooper that she kept it a secret so as not to hold up production. She wrote that she was in so much pain, she couldn't even remember filming one of the exhausting Bob Fosse dance numbers.
The company was filming on the day Dr. Martin Luther King was assassinated. Actress Paula Kelly was so upset that she couldn't work. Director/choreographer Bob Fosse didn't quite understand, as he was so passionate about making the film. Nevertheless, he let everyone go home early.
Shirley MacLaine wrote that Gwen Verdon, who had starred in the Broadway show, suggested to her that she should pursue the lead for the film version. After MacLaine got the role, Verdon generously coached MacLaine on her performance.
The uncredited dance double for Shirley MacLaine later became a famous porn actress under the stage name of Georgina Spelvin.