Apollo Records president Bess German is shown trying to get Mahalia Jackson to record blues because she doesn't think gospel music would sell. In fact, Apollo Records already had an extensive line of gospel records (and they sold) before Mahalia signed with them.
Mahalia Jackson's accompanist, Mildred Falls, is shown as single. She was actually married to Ralph M. Jones, who played organ on some of Mahalia's records. The couple were billed as "The Falls-Jones Ensemble" on Mahalia's 1956 Columbia album "Bless This House."
Apollo Records president Bess Berman is depicted as white; she was really Black.
When Mahalia Jackson burns Russell's dinner, the kitchen appliances are far too modern-looking for 1950.
In the early scene in which a very young Mahalia Jackson is shown listening to and singing along with a blues record, the record is a vinyl LP, a format that didn't exist until 1948, 25 years after the scene supposedly takes place. Also, the phonograph shown couldn't have played such a record even if it had existed.