For some idol groups, their eventual turn to mature concepts happens somewhat gradually, like A Pink or GFriend. On the other side of the spectrum, there’s Girls’ Generation with Run Devil Run.
Coming hot on the heels of Oh!, 2010's Run Devil Run was the aural equivalent of whiplash after that saccharine marshmallow of a track. Prior to Run Devil Run, Girls’ Generation was better known for uplifting teeny-bopper songs like Gee, Tell Me Your Wish, and Baby Baby.
It was only after Run Devil Run that Girls’ Generation started expanding their range on a serious level; immediately afterwards came Hoot, a sultry Bond girl-esque ode to spy movies, the very divisive, almost operatic The Boys (which still never fails to provoke heated arguments), and the energetic, girl-crush-themed I Got A Boy. Every idol group who lasts long enough goes through a cocoon and molting phase; for Girls’ Generation, that entire phase happened nearly instantaneously.