Commissioned by the Parisian chamber music company "La Trompette", the Septet was composed between 1879/1880. Saint-Saëns had been choosy for many years before responding to the request of the founder of this company, Émile Lemoine: "I will make you a concerto of 25 guitars, with trumpet, it's impossible". This work surprises as much by its instrumentation for trumpet, string quintet and piano suggested by Lemoine, as by its stylistic reminiscences to the suites of the Baroque period. Because of his very accessible music, the Septet in four movements quickly became popular and later produced many neo-baroque works. It is published for the first time in a critical edition.