When most three year olds carelessly colour on walls or beat Tupperware containers with old spatulas, Sarah was uncommonly drawn toward the rhythm and cadence of the human voice. In one small moment, a three year old knew more about her life than many grown adults know about theirs. She would not grow up to be a musician—music already lived and breathed in her.

Today, echoes of Billie Holiday, Joni Mitchell and Feist ring out faintly through the structure of Sarah’s artistry. In a modern bl...