Jon Gold’s new single, "Lullaby for a Dream," is an act of gorgeous disorientation. You see the name—a pianist rooted in the intricate soils of jazz—and you prepare for one thing, but what arrives is a mist-laden skiff drifting from an entirely different shore. Gold, a Delaware musician, has composed a piece of British-Gaelic folk, and the cognitive dissonance is half the immediate magic....

Love Ghost from Los Angeles and Wiplash from Mexico make the best song about heartbreaks in the digital age. They meet in the neon-lit streets of modern music. "Left on Read," their fiery song, is a pop-punk blast that makes the fear of unread letters audible. This song stands out because of its strong notes and steady drum beats. They make me think of the...