Sufjan Stevens, “Should Have Known Better.” He’s been missed, not least because in his early career he seemed so prolific. Remember when all the talk about him was how Michigan and Illinois were just the tip of a 50-album project covering every state in the union? “Should Have Known Better” presages Carrie & Lowell, the new album due on March 31. It’s a confidently constructed pop song that hearkens back to early Stevens but with richer, deeper production. Like so much Stevens stuff, it goes on longer than anticipated, given how simple and direct and quiet it is. The extended sense gives it a transcendence, a meditative quality augmented by the pebbles-in-a-pool video.