An analysis of re-orchestrations of Robert Schumann's four symphonies employed by conductor Felix Weingartner (1863-1942). The text includes a brief history of Schumann's orchestral writing career and an overview of Weingartner's life as a conductor. The bulk of the dissertation discusses actual changes suggested by Weingartner (with score examples). Patterns of modifications are identified and discussed as they relate to historically entrenched problems perceived with Schumann's originally employed practices of orchestration. The analysis focuses on overall patterns of alteration imposed by Weingartner and their perceived effectiveness in achieving a noticeably improved aural outcome.