This is based on a stage musical by Lerner and Loewe, who created My Fair Lady, Camelot, and Brigadoon. I I just looked up the plot of the stage musical on Wiki, and the plotline is entirely different from that of the movie. An entire plotline, with Ben Rumson's daughter in love with another miner, was eliminated. I'm not sure why the story was changed so radically. I can't imagine a film producer doing that to My Fair Lady or Oklahoma.