Plot: The first of MGM's phenomenally profitable Jeanette MacDonald-Nelson Eddy musicals, Naughty Marietta takes several beneficial liberties with the libretto of the original Victor Herbert operetta. MacDonald plays an 18th-century French princess who escapes an arranged marriage by posing as a cake girl, a mail-order bride sent to the New World to marry a colonist.
En route,
MacDonald and the other brides are captured by pirates, but are rescued by mercenary
Eddy and his roistering companions. To avoid marrying some lowly farmer or frontiersman, simon-pure
MacDonald intimates that she is a woman with a history, which makes her attractive to the glitterati of old New Orleans. Only
Eddy sees through
MacDonald's feigned naughtiness, and in the end claims her for his own. The most memorable of the
Herbert songs retained for the film version of
Naughty Marietta was Ah, Sweet Mystery of Life, which remained one of
Jeanette MacDonald's signature tunes ever afterward. ~ Hal Erickson, All Movie Guide.