I have watched this movie a number of times over the years, mainly because I love the music. I keep hoping that I will also enjoy the movie. Sometimes the music wins, sometimes the movie loses, and I turn it off.
I just caught it again on TV, after a long avoidance. My first thought was, was this movie colorized? The color was so garish, and the depiction of the "colored" farm hands so out of date, that I wondered whether it was actually filmed in the 30s or early 40s, before color, like the original. So I logged on and found out it was actually filmed in 1951, in Technicolor. There is no excuse for the absurd racial stereotypes by then, at least in Hollywood; but then the whole movie is nothing but stereotypes, so I guess it is an equal opportunity offender.
The real problem is there is not much or a script to hold the musical numbers together. The movie starts with music, and the characters are never really introduced. Stuff just starts happening, and you never quite care about any of the characters. You get the impression someone just kept cutting out dialogue from the script to make room for the musical numbers and keep the movie short - 107 minutes - until there was hardly anything left except the bare storyline. Hey, if a film is good, you don't want to shorten it.
And while the melodies are wonderful, the singing is awful. There is far too much vibrato, more, I think, than you would find in most operas.
Next, if you watch the lips of the actors, you get the impression that all the dialogue is dubbed in afterward. And the acting is weird. In the beginning, it is bad because they are supposed to be bad actors on a showboat. But then they become bad actors in a bad B quality movie.
The best thing that could happen to this movie would be to put the soundtrack in a lifeboat and torpedo the movie. It is offensive to blacks, offensive to whites, offensive to music lovers, and most of all, offensive to movie lovers.