The McGarrigle sisters (Kate died of sarcoma last year) were more successful in their native Canada than in the States, but they were deeply admired by those who covered their songs: Emmylou Harris, Linda Ronstadt, Maria Muldaur, Kate's son Rufus Wainwright.
While it's hard to imagine many pop artists signing up to
write a song cycle based on the history of classical music, for
Amos—whom Deutsche Grammophon approached with this idea—the project
seems almost inevitable.