Little is known about the effects of music on children’s emotions and emotion regulation, as research in this area has been conducted almost exclusively with adults and adolescents. Therefore, the following chapter on children’s musical emotions will briefly outline the development of musical abilities, guided by the question to which extent children’s musical emotions are similar to those of adults and adolescents and the extent to which children differ from them in their emotional musical development. Subsequently, the development and psychometric properties of the “Emotions while Learning an Instrument Scale (ELIS)” for measuring positive and negative musical emotions in children are presented. Finally, we discuss the use of music for emotion regulation, in particular the need for a more differentiated consideration of music according to its positive and negative effects.