Alter Egos is an unconventional covers album, with alternate takes on tracks that the breezy singer/songwriter released just the previous year. But for a short, sweet collection, it packs ample star power—each new version features a different guest performer. “Whole Lot of Heart” begins with spare, stately chords, then shifts tone into a brighter register, opening up with seraphic harmonies courtesy of Tegan and Sara; Sara Bareilles adds depth to “Miss America,” a salute to going against the grain.