Promotional material claimed Betty Compson was an accomplished violinist and was playing live in her musical scenes, but, in actuality, her playing was mimed to previously recorded violin solos by off screen Russ Columbo who also appears on screen as an uncredited member of Gus Arnheim's Orchestra. This information was later revealed by the music's composer, Oscar Levant. Compson did learn to play the violin in her youth and played professionally in theaters and vaudeville since the age of 16. So, her bow movements and fingering appear authentic. Her character in Inside the Lines (1930) also plays the violin.
This was the first "official" RKO Radio Pictures production, but it was released after Syncopation (1929).
In the movie, the character Joe Spring calls his Italian band-mate: Guinea. Guinea is a racial slur first used for blacks or anyone of mixed ancestry. Then, it was more commonly used as a slur towards Italians - in particular, southern Italians. Other movies that use this same racial slur are: The Godfather (1972) and True Romance (1993).
The Kepple character talking to Frederika says, and this may be a slight paraphrase, "Say, what's the 'n-word' in the woodpile?" However the 'n-word' is blanked out of the soundtrack on the TCM print.
Russ Columbo also dubbed the violin hot jazz solo performed by Happy Winter (Ned Sparks) near the end of the film.