As fitness crazes become evermore bizarre (and also awesome—trapeze yoga? Hula hooping? Yes!!), we’re secretly hoping that tap dancing catches on. If it does the credit for all those hipsters tap-tap-tapping away will probably belong to Tilly and the Wall. Percussion? Yah, they’ve got it, in the form of some seriously happy feet. In addition to being a great gimmick—corny and folksy and seriously hip—the tapping works with their brand of pop. Which you......