I Can't Stop Listening to Babymetal, the World's Heaviest Teen Pop Band Andy Cush · 11/06/14 02:35PM On Wednesday, the Japanese heavy metal/teen-pop hybrid band Babymetal played a nearly sold-out show at New York City's Hammerstein Ballroom. I didn't go, and after watching a few of their videos this morning, I'm really, really regretting it.