I always thought Rosalind Russell was dreadfully miscast in the movie version of Gypsy. There are many arguments that could be made in support of this position but I'll make two. One is that she wasn't "musical" enough, as proven by the fact that her singing had to be dubbed. Yes, I know Ms. Russell could sing and that she sang in other films without being dubbed, and dubbing sometimes works. But to me, she feels dubbed throughout the film. She doesn't move like a musical performer or gesture as if she's one with the music.
But the bigger issue for me is that Momma Rose, as depicted in the show Gypsy, is a hardscrabble fighter who's struggling to keep food on the table, and who also is trying to live vicariously through her daughters. Momma Rose herself couldn't have been a star but she's going to do the next best thing and shove at least one of her daughters to center stage. And that's where Rosalind Russell really doesn't work for me. She just looks like a rich, successful movie star. For her to play a woman who has to struggle is like…well, imagine Warren Beatty playing a guy who couldn't get laid.
That, to me, is the Catch-22 of Gypsy: To play Momma Rose, you need a star because only a star could fill the attention-holding demands of the role. But the role is that of a woman who is not a star, which is why Ethel Merman was probably such a great choice. Merman was a star but she sure didn't look like one…and unlike Rosalind Russell, didn't come off as a person of privilege or breeding. It's a shame she didn't get the movie.
But what if she had? We'll never see that but in an interesting experiment, a fellow on YouTube imagined what it would have been like if Ethel Merman, instead of Lisa Kirk, had dubbed Rosalind Russell's singing voice in the film. It might have gone something like this…