The symphonie concertante, a product of the late eighteenth-century Parisian concert societies, provided a vehicle for display of the virtuoso style sought by contemporary audiences. The works of the Chevalier Joseph Boulogne de Saint-Georges, one of its chief exponents, served as strong influences on the development of the form and its diffusion throughout Europe. The symphonies concertantes of Opus VI, No. 1 and Opus X, No. 2 (according to thematic numbering of Barry S. Brook) date from ca. 1775 and 1779 respectively. A complete set of parts for each is to be found in the private collection of M. Andre Meyer in Paris (Opus VI) and in the Universitetsbiblioteket at Lund (Opus X). The thesis contains background material on contemporary Parisian musical society and the life of Saint- Georges, and a modern scoring of the above symphonies concertantes with analysis and conclusions.