In the very early 1930s, operettas were quite popular. Films like "The Rogue Song" and "Sweet Kitty Bellairs" were just a couple such movies and less than a decade later the style was resurrected with the Jeanette MacDonald and Nelson Eddy films. However, by the mid-1940s the genre was just about dead due to changing tastes and when seen today the pictures come off as very strange and old fashioned. Based on what I've seen, I can understand why they are no longer popular.
When "Sweet Kitty Bellairs" begins, a group of rich 18th century folks are heading to the spa town of Bath for a holiday. However, their carriage is waylaid by bandits and the cheeky masked leader decides that instead of stealing all their valuables that he'd just take a kiss from Kitty. While she protests, it's pretty obvious to tell that she is quite taken by this stranger. And, what's also obvious is that the nice man she later meets at the spa is actually the bandit dressed in the fine clothes of a gentleman. What will come of this? See the film (or, better yet, don't).
This film was creaky with age and left me very, very bored. Much of the music just put me to sleep but the bad acting made it even worse. Particularly bad was Ernest Torrence who just didn't seem to know how to deliver his lines...though he would improve in later films. Perhaps he just wasn't used to sound films. All I know is that the movie left me very cold and this sort of silly fluff just didn't appeal to me. Far less well made and interesting than a MacDonald/Eddy film.