This dissertation discusses two flute works by Joan Tower (born 1938). The performance medium consists of flute alone, Hexachords for Solo Flute (1972), and flute and orchestra, the Flute Concerto (1989). The discussion on Hexachords consists of a theoretical analysis; discussion on the Flute Concerto pertains to Tower's flute writing through an investigation into her musical language and specific performance techniques. Numerous examples are included to illustrate various aspects of Tower's style. Conclusions follow. The purpose of the paper is, first, to illustrate that basic knowledge of the twelve-tone method can bring a composition out of uncertainty for the performer and allow him to present what is unique within it. Secondly, it is to investigate the stylistic maturation of Joan Tower's flute works. In order to facilitate a better understanding of Tower's music and to provide commentary about the performance of each work, the writer has quoted from personal interviews with the composer and with flutists Carol Wincenc and Patricia Spencer, to whom the works are dedicated.