Children hear music in the background of a large variety of situations and activities. Throughout development, they acquire knowledge both about the syntactical norms of tonal music, and about the relationship between musical form and emotion. Five to six-year-old children heard a story, with a background ‘happy’, ‘sad’ or no melody. Results show that background music affected children's interpretation of the story: ‘happy’ background music led to positive interpretations, whereas ‘sad’ background music led to more negative interpretations of the story. The effect of ‘happy’ music was stronger than that of ‘sad’ music. Implications for education are discussed.