One of the odder musical sub-trends in rock history is how seemingly once a decade or so, there's a burst of artists directly inspired by the music of the 1930s and '40s, like Harpers Bizarre or Spanky & Our Gang in the '60s, Bette Midler and Dr. Buzzard's Original Savannah Band in the '70s, U.K. sensation Mari Wilson in the '80s, and the Squirrel Nut Zippers in the '90s. In the early 2000s, there's already the Puppini Sisters' Andrews Sisters fixation and Michael Bublé's blatant appropriation of the young Frank Sinatra's mannerisms. Add to this Victoria Hart, a young jazz-pop...