I cannot argue with other comments that the story line focuses more on the romance between the Mary Martin and Allan Jones characters, much in the manner of "Showboat", than on the life of Victor Herbert. But in the 1930's, would that have been a box office draw? Instead of the Life of VH, perhaps it should have been the Music of VH. There is an abundance of this.
For me, the thrill of the movie came near the end of the movie when Susanna Foster sings "Land of Romance". It has been over a decade since I caught this movie for a second time at a local 'old movies' theater. At first the audience was stunned; then it burst into spontaneous applause. I remember the shivers running up and down my spine. My trivia memory recalled the information provided to an inquiring public by a local journalist when the movie first came out back in the late 1930's. 'That note hit by Miss Foster was a far F above high C.'
She may not have had four octaves a la Yma Sumac but the then teen-ager certainly had a range!