Flack got her first teaching job when she was 19 years old.
"I taught 12th grade English literature, but every two-and-a-half, almost three weeks, I would see at least every child in that school, and this was what they call a coordinated school, which meant for that area it was the only Black school available," Flack told NPR in 2006. "And so I had kids from preschool all the way through 12th grade, and I taught every one of them something musical."