Music always lures Ricky Montgomery back. He blames the internet. First a devotee of the Vine underground, and now—nearly a decade and several jobs later—an unexpected hitmaker, the Los Angeles native has spent the last few years trying to reconcile with his artist self. He recently surpassed 1 billion global streams thanks to Platinum indie-pop hits “Mr. Loverman” and “Line Without a Hook.” But those songs, written when he was a teen, have come to feel like they were by a whole other person at least to Ricky.