Francesco Geminiani was highly regarded as a violinist, composer, and theorist during the late Baroque era. During his lifetime he was considered equalin status to the foremost composers of the day; however, relatively little information is available regarding his life and works today. This lack of information is largely a result of controversy among his peers regarding the merit of his work, specifically in reference to melodic style, structural consistency and harmonic practices. Critical views of such authors as Sir John Hawkins and Charles Burney have been reflected in later historical writings, considerably suppressing further interest in the composer. The first objective of this thesis is the examination of Geminianis 1752 treatise, Guida Armonica, its content, and implications for potential harmonic and structural functions. The second objective is to identify specific characteristics of Geminianis music that distinguish him from other composers of the period. Comparative analyses of selected movements by Geminiani and his teacher, Arcangelo Corelli, identify traits unique to Geminiani. The third objective of this project is to explore possible relationships between the work of Geminiani and the content presented in Guida Armonica. It is the intent of this study to provide expanded information about Guida Armonica and Geminiani’s compositional style, identify possible parallels between the music and treatise, and explore how the distinguishing stylistic details of his work may correlate with the criticisms he faced.