On their rides to school in the morning, Shelby Lynne says, her mother taught her daughters to sing harmony. Victory Tischler-Blue/Courtesy of the artist hide caption

itoggle caption Victory Tischler-Blue/Courtesy of the artist

Tegan and Sara celebrate Christmas in 1985. The sisters are featured on a new holiday album, Gift Wrapped II: Snowed In. Courtesy of Tegan and Sara hide caption

itoggle caption Courtesy of Tegan and Sara