abstract: W.A. Mozart was a masterful creator of music and drama as well as a keen observer of human relationships. Librettists were enamored of his ability to bring their words to life with his music. His truthful portrayal of human relationships, particularly involving women, was highly influenced by his own life experiences. Through these relationships he learned to create characters and music that clearly depict female sibling relationships in the eighteenth century. A review of educational opportunities for women during the eighteenth century, Mozart's personal relationships, as well as selected roles in his operas will help to explain Mozart's portrayal of the eighteenth-century female sibling stereotypes. While Mozart's self-centeredness is well documented in biographies by Cliff Eisen and Ruth Halliwell, and the argument can be made that he surrounded himself with females who fulfilled his needs, he was often drawn to operas in which he could advocate musically for a female character's liberation from the overbearing influence of powerful men. Although Mozart's "musically empowered" women appear in nearly every opera, for the purpose of this paper, I will focus on the characters of Così fan tutte's Fiordiligi and Dorabella, and Le Nozze di Figaro's Countess. First, however, a closer analysis of Mozart's early life and his relationships with his sister and mother is necessary. The ways Mozart set characters created by DaPonte and Beaumarchais cannot be separated from the ways he was taught to appreciate females in his family of origin. Social structure during the eighteenth century dictated a woman's education, responsibility to her family, and therefore, played a fundamental role in defining her life. This situation often created expectations within the birth order that had an impact on sibling relationships as well as individual personalities. Many social and familial influences are represented through the operas of Mozart. Così fan tutte (January 26, 1790) and Le Nozze di Figaro (May 1, 1786) both contain a central female sibling relationship that reflects aspects of Mozart's relationships with women throughout his life. / Dissertation/Thesis / D.M.A. Performance 2010