Tailor, road sweeper and glass-blower discover the possibilities for performing music with their tools. But the audience booed. Even after persistent practise and a beautiful performance the audience still does not understand them. Professor Balthazar discovers in space a lonely singer. Our three enthusiasts travel by spaceship to the lonely singer and make a friendship. Music brought them together. Professor Balthazar appears with his friends at least once a month at the performances of the Star Quartet. In such way the circle of fans grows little by little.