It’s not surprising that Babymetal has gone viral. The trio, bringing the seemingly disparate worlds of idol pop and heavy metal together, is a visually striking project perfect for the “weird Japan” fans on the Internet.

What’s surprising, however, is seeing Babymetal’s eponymous debut top the iTunes heavy metal charts in the United States, Canada and Britain — and climbing as high as No. 35 on the American iTunes album chart. Sonically, Babymetal should be one cool idea driven into the ground — how many songs merging cutesy choruses with guttural shrieks can a headbanger take? — but the project boasts just enough musical diversity to make for a good listen.

The dominant sounds throughout “Babymetal” are power chords, breakneck drumming and throaty howls offset by cheery singing, and the group lags when sticking strictly to that combo. However, many of the tracks make subtle changes to keep the album humming along. “4 no Uta” zips from guitar workouts to tropical lounge interludes, while “Ii ne!” takes a breather for a group rap that sounds like it has been ripped from the once-hip witch house subgenre. The lyrics focus on typical idol-pop topics — chocolate, the struggle of waking up — but also spin into subjects such as bullying and, on “Onedari Daisakusen,” tricking your dad into giving you money.

The album’s musical variety stems from the diverse collection of writers and producers that have been brought onboard the Babymetal project. It’s not surprisng to find the likes of Narasaki (of metal act Coaltar Of The Deepers) and Takeshi Ueda (Mad Capsule Markets) in the credits — but it is seeing Vocaloid producer Yuyoyuppe, who brings in EDM-fest-ready bass freakouts to some of the songs.

The best moments on “Babymetal” come when the group ditches the gimmicks. YouTube hit “Gimme Chocolate!!” adds in growls, but it’s the unit’s most straightforward pop song — and an extremely catchy one. Singles “Megitsune” and “Doki Doki Morning” are similarly constructed and memorable.

“Babymetal” indulges in the ridiculousness of both the idol scene and heavy metal, but goes beyond being a joke. It’s a good full-length better than many more “serious” mainstream metal albums (it’s a less cynical, more pop friendly version of Maximum The Hormone’s last album, “Yoshu Fukushu”). Babymetal is first and foremost a visual WTF, but the act (and the musicians behind it) deserve credit for a solid album.