Roberto Gerhard was a twentieth-century Spanish composer known for his unique treatment of the twelve-tone system. A student of the Spanish nationalist composer, Felipe Pedrell in Barcelona and also a pupil of Arnold Schoenberg in both Vienna and in Berlin, Gerhard's musical trajectory led to a synthesis of these disparate compositional traditions. In this dissertation I will explore the development of Gerhard's compositional procedures. Here, his first string quartet, composed between 1950 and 1955, becomes a useful tool to illustrate how he made the transition from one musical style to another. Gerhard's first string quartet, composed between 1950 and 1955 exhibits various experimental formal procedures but is governed by a single twelve-tone row. The work is composed in the twelve-tone idiom, but nationalist elements decorate the musical surface. The first movement follows the classical model of sonata-allegro form, while mathematical proportions govern durations and formal elements in later movements. I will first investigate Gerhard's musical language and pitch material and then consider the challenges raised by implementing sonata form outside of a tonal idiom. I will then examine his unique mathematical approach to formal design in the third movement. In addition to the string quartet, I will explore Gerhard's treatment of form in such works as his Wind Quintet (1928) and Metamorphoses--Symphony no. 2 (1957-59). / text