Few artists of the ‘10s have been as instrumental as Frank Ocean in inspiring a generation of DIY songwriters with old souls to blur the boundaries of R&B. Steve Lacy's lo-fi funk jam “C U Girl” aches with a familiar sense of longing, and on love-drunk piano ballad “Apricot Princess,” Rex Orange County channels California sunshine from London. On the breezy “4EVER,” bedroom pop star Clairo makes existential angst sound quietly catchy.