When Johann Sebastian Bach visits one of his sons in Potsdam in 1747, he is summoned to the royal court, where he meets the young monarch Frederick II of Prussia. The latter appreciates Bach's genius, but detests being overshadowed. His court composer Quantz has accepted this restriction, but not his sister Amalia, who has a crush on Bach's headstrong son Friedemann. In the course of Bach's visit, a battle of egos breaks out.