I just watched Maytime on TCM. Overall I feel that this movie is a bit too long and dull and the outdoor scenes (e.g., Maytime and Paris) are a bit too stereotypical and precious, but it contains two really strong musical numbers that saved the movie for me: the first occurrence of "Will You Remember (Sweatheart)" and the climactic "Czaritza" duet. Not only are the music and singing and orchestration great, but the acting of Eddy and MacDonald is very believable. Jeanette MacDonald looks beautiful in this film, and the costumes, scenery, cinematography, etc. are all first rate. I also enjoyed the reprise of "Will You Remember (Sweatheart)" at the end of the film, but for me it lacked emotional impact because the camera was not focused on the actors' faces. For me the message of the film as delivered by MacDonald to the young woman was a clunker as there was obviously a middle course. And finally the major plot twist near the end of the film was jarring. I can imagine several more realistic scenarios.
