The central character "Julius" takes the children on an exciting journey through the centuries, distant countries and the world of music, just like in a musical theatre. Together with him, they meet medieval minstrels, Johann Sebastian Bach, a Japanese monk, an expert on bird calls, learn about different recorders and much more. Julius is curious and bright, he asks many questions and encourages the children to do the same. A lively dialogue develops in which the children learn a lot about music. The other three musicians repeatedly slip into different roles during this concert and actively involve the children in the action.