Factual errors: In Max Dreyfus' office, Oscar Levant while looking at Georges' score of "Swanee" hums a perfect forth (D down to A) and says, "A diminished 9th." In the next scene Max Dreyfus also refers to the uniqueness of a diminished 9th. In Swanee there is no diminished 9th. There are enharmonic equivalents ie. a C# melody against a Db bass which sounds like a diminished 9th. It is acually a sharped major 7th. The interval of a diminished 9th ie. (C up to Dbb or C# up to Db)does not happen in Swanee. Both a diminished 9th and an enharmonic equivalent will sound like a perfect octave when played eight notes apart.
Factual errors: The aria, "Summertime", from "Porgy and Bess", is performed first by the character Clara, and later, in a tragic scene, by Bess. But not only by Bess, as the film seems to depict. The film also gives the impression that the first verse is performed by chorus, which is not the case. The chorus only hums an accompaniment.
Factual errors: The opening credits say "Music and Lyrics by George Gershwin and Ira Gershwin", when in fact George wrote the music and Ira wrote the lyrics. None of the other lyricists in the film, including DuBose Heyward, who wrote the lyrics to "Summertime", are credited.