Walter Gerber is an engineering draughtsman, and works at a filling station too. In his spare time he plays jazz trumpet with his friends, to the disapproval of the older generation. The American jazz clarinettist Bert Nicholas spots him and offers him work in America at an enormous salary. Will he be tempted, or will he follow convention and pursue his career and stay amateur? There are extended concert performances by artistes of the day; Freddy Quinn is the most long lived.