For your pleasure, here's Ava Gardner (dubbed by Annette Warren) singing Jerome Kern and Oscar Hammerstein II's "Can't Help Lovin' Dat Man of Mine" from the 1951 musical Show Boat. Ella Fitzgerald, Liza Minnelli, Barbra Streisand, Lena Horne and Judy Garland all covered this, and Helen Morgan made it famous in the original 1927 Broadway show. But Gardner singing in the context of the movie is sublime. (Gardner's voice wound up on the soundtrack album of the film Show Boat, but not in the film itself.) She's playing a character passing for white who could have been played by Horne, but wasn't.