하트번 (Heartburn)

Sunmi has always understood that heartbreak is more interesting as spectacle than confession, and this track leans fully into that theatrical instinct. The production borrows from early-2000s European club music — a pulsing four-on-the-floor kick, strings that feel melodramatic in the best possible way, synth stabs that arrive like emotional punctuation. There is something almost operatic about the construction, a sense that the pain being described is being performed on a very lit stage for a very large audience. Her voice sits in an interesting register here: technically light, but emotionally pressurized, capable of sounding both fragile and composed within the same phrase. The song uses the physical metaphor of heartburn — that burning, persistent discomfort in the chest — to describe the specific torment of someone who will not leave your thoughts even when you want them to. It is not the sharp agony of a fresh wound but the dull insistence of something half-healed that keeps reopening. This kind of layered metaphor is where Sunmi excels as a songwriter, finding images that are bodily and precise rather than abstract and vague. It is a song for driving alone at night when you are not sure if you want to feel better or just feel everything as loudly as possible.