We know that pupil talk is an integral part of the learning process. Previous research has not viewed affective engagement in a music composing task as a vehicle for developing higher order discourse skills. The aim of this study is to evaluate the significance of teacher questioning in encouraging quality dialogue with children during music composing. This paper reports on an empirical study investigating dialogue with young children during an imaginative music composing task. Pairs of children aged 6 and 7 years were audio recorded as they talked to each other and the researcher about the task. The dialogues between the researcher and the pupils highlight the importance of teacher questioning in encouraging young children to engage in evaluative talk and problem solving, through discussion and musical experimentation. Significantly, the findings suggest that young children reflect on the learning process through meta-cognitive thinking. They also highlight the significance of the role of the teacher in scaffolding and encouraging children’s thinking and learning through dialogue, and the importance of talk and evaluation as a part of reflective music composing activities.