This study considers the way children listen to classical music composed for them and the effect of age on their spontaneous invented notations and verbal responses. The musical selection is a piano piece for children by Claude Debussy:"'Jimbo's Lullaby" from "Children's Corner". Two hundred and nine children 4-9.5-years-old listened to the music and expressed their impressions graphically and verbally. Three systems of conceptualisation emerged: Associative responses (A-responses) suggesting metaphoric interpretation, Formal responses include references to sound and Compound responses integrating Associative and Formal expressions. Results show a strong dominance of Associative over Formal and Compound categories at all levels and a gradual decline of A-responses with age. Studying children's responses to a classical work addressed to them paves a way to a greater understanding of their music perception. This bears a number of implications for music educators who introduce young children to classical music and for composers of music for children.