너로 남아 있어줘 (오 나의 귀신님 OST)

Kassy occupies a distinctive space in contemporary Korean ballads — she draws on American soul and R&B phrasing while applying it to melodies that are unmistakably Korean in their emotional directness. "너로 남아 있어줘" from Oh My Ghost moves over a mid-tempo groove, the rhythm section light but present, giving the song a pulse that sets it apart from the more static piano ballads dominating Korean OSTs. The production layers warm electric guitar lines beneath the vocals, lending a vaguely late-night urban feel. Kassy's voice has grain to it — a slightly rough texture that suggests lived experience rather than studio polish — and she deploys it with remarkable control, choosing not to belt when the song might support it, letting restraint do the emotional work instead. Lyrically, the song asks someone to remain — to stay as they are, unchanged — a plea rooted in the fear that love's evolution means loss of the specific person who was loved. In the drama's context of a ghost seeking to remain in the world, this desire for permanence acquires additional poignancy. Best heard driving alone at night, windows cracked, when the city feels both intimate and anonymous.