You know a genre has arrived on the global stage when the Japanese music industry does something incomprehensible with it. Tokyo trio Babymetal graft robotic metal drumming and grim guitar crunch onto maniacally cutesy, achingly sentimental tunes, sprinkle them with goofy sugar-rush techno, and crown them with the gleaming superhuman voice of a computer-assisted teenager backed by two gleefully shrieking little girls—and by the awesome power of the J-pop idol machine. Lead singer Su-Metal is 17, while sidekicks Yuimetal and Moametal (credited with “scream, dance”) are both 15, so Babymetal seem due for their first personnel change since forming in 2010—unless their success in the States, where members of pop groups aren’t seen as quite so interchangeable, buys them a reprieve. On this tour to promote the U.S. release of their self-titled 2014 debut, they’re backed by a four-piece live band, and their Chicago date sold out in 30 minutes. Babymetal may owe their audience here to novelty, but at least they’re genuinely novel. “Gimme Chocolate!!” opens with swooping, stuttering trance keyboard and the sidekicks chirping through what sounds like a nonsense playground chant, all set to viciously compressed gunmetal chugging—and then Su-Metal explodes into the song with an absurdly sunny chorus. The beautiful, brutally catchy “Megitsune” alternates between high-powered jets of frothy synth and what might be koto and shamisen (or electronic approximations), conjuring a sort of ersatz Japanese folk whose ghostly melancholy even colors the song’s gurgling, down-tuned deathcore breakdown. Elsewhere the album dips into sentimental piano balladry, fake trap rap, vacuum-cleaner death growls, imitation harpsichord, farty underwater dubstep, and reggae that sounds almost sarcastic. As frisky and accessible as this stuff is, it can match the murkiest, most tangled avant-garde metal for sensory overload. “How in Sam Hill did this come to exist?” your brain may ask. Precision-engineered, big-dollar pop product isn’t supposed to scramble genres like a preschooler building a Lego fortress for Darth Vader and then crashing Barbie’s Glam Convertible through it. But once you get done standing there with your mouth hanging open, you’ll be smiling till your face hurts. —Philip Montoro