This is an often very funny movie, with something of a hole in the middle of it.
Lily Pons, though a fine singer and an attractive woman - who didn't photograph well, at least in this picture - did not have the charisma to carry off a movie. If you compare her to Jeannette MacDonald or Grace Moore, her equivalents at MGM and Columbia, you will see what I mean. She isn't helped by the fact that she is given an unsympathetic role. Rather than another replay of the singer who dreams of singing opera and disdains popular music, this movie would have been much better if she had been presented as a singer who wanted to do both, and fight against the prejudice that held that opera singers shouldn't do popular music. The best numbers in this movie are when she does pop music - especially "Hitting a new high" - so her disdain for them doesn't make her attractive to the audience. The staging of the Mad Scene from Lucia di Lammermoor is downright bad, and would have confirmed opera-haters' views of why opera wasn't interesting. She just walks around with her arms extended gazing up at the sky. You would have NO idea what the number, a very dramatic one, is actually about from watching her performance of it in this movie.
What makes this a fun movie is the character parts - Jack Oakie, Edward Everett Horton, and Eric Blore - who are given really first-class material and a LOT of screen time, with which they do a really first-class job. Oakie and Horton come off as a quirky couple, with Horton as the straight man and Oakie as the guy with all the jokes. With many 1930s musicals you want to delete the dialogue scenes and just focus on the musical numbers. Here, frankly, it would be tempting to eliminate most of the musical numbers and the romantic scenes (which are few) and focus on the scenes with Oakie, Horton, and Blore.
Though I would save the scene in "Africa" where Pons appears in a lagoon singing to exotic birds. It's the most charming number in the movie, and nicely done.