Flack lived with a musical family, born in Black Mountain, North Carolina to parents Laron Flack, a Veterans Administration draftsman, and Irene Council Flack a church organist, on February 10, 1937 (some sources also say 1939 - 1940 Census states Roberta was 3 years old) and raised in Arlington, Virginia. Growing up she often accompanied the choir of Lomax African Methodist Episcopal Zion Church by playing hymns and spirituals on piano, but she also enjoyed going to the "Baptist church down the street" to listen to contemporary gospel music, such as that performed by Mahalia Jackson and Sam Cooke.