This was the last film for George Gershwin, who died before filming had begun. He and his brother Ira Gershwin had been hired to write the songs, which were not yet completed. Composer Vernon Duke took his place and co-wrote "Spring Again" with Ira, as well as the music for "Romeo and Juliet Ballet" and "Water Nymph Ballet." In his autobiography, Duke also claims to have worked on the hit song "Love Is Here to Stay."
George Balanchine wanted to film a ballet of Gershwin's "An American in Paris" for this movie, He choreographed and rehearsed it for three weeks but was told by Goldwyn that "the miners in Harrisburg wouldn't understand it." The ballet was later used in An American in Paris (1951), choreographed by Gene Kelly.
The American Ballet of the Metropolitan Opera is listed in the cast in the opening credits, but not in the end credits. Because of this, the IMDb cast listing uses the opening credits first, and fills in the rest of the cast from the end credits.