Mezzo-soprano JoyceDiDonato returns this weekend for her annual series of master classes for young opera singers. Watch them live, in partnership with medici.tv, April 21, 22, and 23 at 4 PM at carnegiehall.org/medici. April 22 will also be available at facebook.com/carnegiehall. Send in any questions for JoyceDiDonato throughout the workshops using #AskJoyce.