Ella Yelich-O’Connor, known to the world as Lorde, is embracing a sunnier and more analog sound, full of plucked acoustic guitars and brushed snares. Since releasing her breakout single, “Royals,” in 2013, she’s made the most of hook-heavy pop songs constructed from a palette of overcast electronic sounds. “In the past,” she says, “I’d hear an acoustic guitar and I’d …