Scott Bradlee's Postmodern Jukebox

How did Miley Cyrus' "We Can't Stop" become a '50s-style doo wop number? Since when was Meghan Trainor's "All About That Bass" about an upright bass fiddle? At what point did Macklemore's "Thrift Shop" evolve into a '20s hot jazz tune? And whose idea was it to rework Lorde's "Royals" into a polished ballad sung by a sad clown? It's all part of th...