The picturesque castle of Tiefenstein, a boarding school, which serves as a new home for musically gifted orphans, is expecting high-ranking visitors. The American sponsors have just announced their surprise visit to insure themselves of the pupils’ progress. But the trouble is that clever director Himmelreich has just reduced her teaching staff in order to save money. Now, she has to compensate as quickly as possible to pep up her unmusical disciples. In her distress, Himmelreich hires Peter Hagen – who admittedly has no understanding of classical music but is a great jazz musician.