Heartburn by Alicia Keys is a soulful R&B song that delves into themes of love, betrayal, and emotional turmoil. Alicia Keys sings about the intense and painful feelings that arise when trust is broken in a relationship, likening the emotional pain to 'heartburn.' With powerful vocal delivery and heartfelt lyrics, the song captures the raw essence of heartbreak and the internal struggle of dealing with deceit. Poignant moments in the song include the lines where Alicia describes the metaphorical 'burn' she feels, emphasizing the deep emotional scars left by betrayal.