"Barbara Allen" is a traditional folk ballad that tells the story of a young woman named Barbara Allen and her love for a man named John Graeme. The song typically depicts themes of love, loss, and regret, as John falls ill and expresses his love for Barbara, who initially rejects him. The ballad has been passed down through generations and has many variations across different cultures. It is often performed in the style of American folk music and has been recorded by various artists, making it a significant piece in the folk music tradition.