"Le Tambourin", a Montmartre nightclub, is on its way down. Although it can boast great performances by the alluring Les Bluebell Girls and by Jacques Hélian's lively Big Band the venue does not attract people anymore. Nightclub patrons now prefer the jazz cellars of Saint-Germain-des-Prés. Taking this new taste into account, the staff of the "Tambourin" and Jacques Hélian decide to set up their own club, "La Pivoine Ecarlate". They are joined by Pâquerette, a flower vendor and amateur singer, and by Jean-Pierre Francis, an existentialist poet...

Jacques Hélian, an attractive charm singer, too stifled by the jealousy of the radio director's niece, flees with his orchestra, on the advice of his secretary Bob. They fail in a small village, where there is a boarding school for young girls. Bob responds to the love letters the teacher sends to the handsome singer.