Rio Bravo is Howard Hawks and John Wayne's right wing answer to High Noon (a movie Wayne called "un-American"). John Wayne is a small town sheriff who's holding a big ranch baron's brother in his small jail until the U.S. Marshall comes through town. The only help he has is an ex-deputy who has become a drunk (Dean Martin), a young gunslinger (Ricky Nelson) and a crippled deputy (Walter Brennan).
There are a couple of song performances in Rio Bravo. Dean Martin sings ""My Rifle, My Pony, and Me" with Ricky Nelson joining in on the song. This is followed by Ricky Nelson singing the old folk song "Get Along Home Cindy" with Martin and Walter Brennan accompanying him.
Dean Martin did a pretty good job as Dude in Rio Bravo and considering he was acting with veteran actors John Wayne, Walter Brennan, Ward Bond, and Angie Dickinson, I think that says a lot about his acting ability. On the other hand, Ricky Nelson was way out of his league and it really showed. You could tell in many scenes he was really trying (several times he decided
acting was running a finger up and down one side of his nose), but his
character never rang true and he was rather an ill fit in the film. Something about Nelson made it look like his mother had dressed him up in his best cowboy outfit and sent him straight from the Ozzie and Harriet set to go play with the big boys. Since his acting was about the same as it was on his family's TV show, it doesn't stretch the imagination too much to believe in this scenario.