I definitely can't agree with the previous comments. This movie is very good and very funny. It's not a De funès Movie, but a Branquignol's one, with Robert Dhery as himself, Colette brosset as a delicious ingénue, and De Funès is "le poulet" ( the chicken, this is the name we give to the policemen). He has only a supporting role. Of course, Mario David is the beautiful muscular man, jacqueline Maillan is herself ( Madame Maillan, the proprietary of the theatre) and Jacques Jouanneau the régisseur. Raymond Bussières is as good as usual,playing Raymond le plombier... the scene with Rosine Luguet at the beginning is really funny,and when he speaks to Robert Dhery about the diameter of the tubes it's very realistic. I'd say Jacques Legras ( as himself) is the main character. He is very good. Too bad he didn't make a great career later.
Well, the choreography is a parody of french music hall. Don't expect it to be good. it is not a musical movie but a parody. The 'défilé sans robes'(the dresses didn't come in time, so the girls make the show in underwear but Jacques Legras makes comment about the non existent taffetas dresses) is hilarious. Overall it is a good funny movie, a good adaptation of the stage performance.
There are many nude scenes, but this is no problem as it is quite normal for a french cabaret ( only Americans can pretend to make a movie about french cabaret without naked girls).
Louis de funès became a big star later.... In Pouic Pouic He was the husband of Jacqueline Maillan, and in Le petit Baigneur we find again Robert Dhery, Colette Brosset and Jacques Legras.... In Oscar mario David plays the same role, in "le grand restaurant" there is the same pianist and so on. This movie is full of reference for later movies of De Funès. I must admit only french from France can get all the fun from this movie and it is for limited audience, but it's from a time, and made by people who didn't even think their movie could be watched overseas or could last for 50 years. 'Vos gueules les mouettes' and 'Allez France' or les tontons flingueurs are better references (IMO) than la cage aux folles.