Here we are, finally. “Yummy” is a return to his … roots? A modest and lazily seductive number, it’s the most overt pivot to R&B he’s released (apart from his overlooked acoustic-ish work). He sounds comfortable, but also choppy, thanks to the particularly hiccupy patchwork that’s the hallmark of modern pop production. And while his syllables glide easily, he’s hobbled by lyrics that feel awkward and a little hasty (“Rolling eyes back in my head, make my toes curl, yeah, yeah”). When that other Justin — Timberlake — made his R&B transition all those years ago, he was bolstered by some of the most adventurous production of the day. But the choices here are safe, never testing nor encouraging Bieber. It’s a step in the right the direction, but the campaign continues. JON CARAMANICA