Thibaut (Benjamin Lavernhe) is an internationally renowned conductor who travels the world. When he learns he was adopted, he discovers the existence of a younger brother, Jimmy (Pierre Lottin), who works in a school cafeteria and plays the trombone in a small marching band. Everything seems to set them apart, except their love of music. Sensing his brother's exceptional talent, Thibaut decides to remedy the injustice of fate.