Toni Harper's childhood was made of the magic any aspiring adult artist would kill for: a platinum record, a performance at Carnegie Hall, evenings spent sharing a stage with such performers as Cab Calloway, and invitations to appear on television with Frank Sinatra, Perry Como, Milton Berle, and Ed Sullivan. And all of the magic unfolded before she'd turned 12 years old.
The jazz vocalist, who now goes by the name Toni Dunlap, got her big break in 1945 when she went up against a couple hundred other kids at an audition held by choreographer Nick Castle. Harper, who had been...