The purpose of this thesis is to show the development of the trombone, in form and music, and its use in the orchestra through the times of Beethoven and Schubert. Since very little material has been presented concerning the history of the trombone, it is hoped that the illustrations and explanations contained herein will be a contribution toward a representation of music from different composers and periods. The music covered gives a picture of the use of the trombone from the Renaissance through to the beginning of the Romantic Period. The results of this study are presented in three main sections: (1) The history of the trombone in the Renaissance; (2) The history of the trombone in the Baroque; (3) The history of the trombone in the Classical Period, and up to the time of Schubert.