By analysis, certain aspects of compositional process and style are discovered- Cooper’s works have grown from the pandiatonic style of his early years to an open style characterized by clear structure, however veiled, by lyrical themes of eleven or twelve notes, by free twelve-tone and contrapuntal techniques, by use of some unusual and effective textural sonorities, and by a logic, growth and unity of ideas throughout each work. Interviews with the composer allcry careful questioning and cross-examination of his compositional process and his aesthetic and philosophical views, as well as provide factual data on the background and reasons for writing a particular work. In the interview. Cooper reveals that basic structure is the initial consideration in his compositional process. When he has settled that issue, he can begin to develop the melodic motives of the quartet. Sketches are used to work out complex contrapuntal passages, but are rarely necessary otherwise. Notating a work is relatively rapid once its composition is more or less complete in his head. A few notes or markings may change from the original draft to the final copy; however, these are usually minor. An exception occurs when an intellectual premise may have prevailed over musical instincts. In this case, Cooper feels the ear must be the final judge. Variation, proportion, and unity are important philosophical or psychological concepts that Cooper incorporates into his works. More often they figure in the composer's instinct rather than in a deliberate or programmed manner. In addition, Cooper answered questions on the historical background of each work. Studies on works by significant living composers present the obvious appeal of personal discussion with the composer in an effort to understand his processes and preferences. Very few composers have made an effort and many are reluctant to describe the fundamental aspects of their style and the reasons or inputs behind it. While in-depth analysis may reveal stylistic qualities, the findings are greatly enhanced by responses to the penetrating questions that surface in such an analytical study -- responses that can only be rendered by the composer. Current history and current musicology can supply information for present understanding and vital resources for future considerations.