This paper investigates Ronald Stevenson's unique treatment of large-scaled structure in his Passacaglia on D S C H. This piece's unusual eighty-minute length, use of traditional forms and unusual piano techniques, musical references to other cultures and a massive triple-fugue over a ground bass will be examined as they relate to its overall form. The elements of rhythm, melody/mode, harmony, counterpoint, piano techniques, and tonality are also used as means of highlighting many unifying elements of the piece which contribute to its overall cohesiveness. Tributes to other composers, among them Dimitry Shostakovich to whom the piece is dedicated, are discussed in addition to many references to world cultures and events which support Stevenson's views on what he terms world music. Rarely is a piece written that encompasses such a wide range of musical elements that possess the ability to engage an audience for an uninterrupted length of eighty-minutes. As of yet, an in-depth scholarly investigation of Stevenson's treatment of formal unity in this landmark piano work has not been done. This analysis reveals Stevenson's approach to composing in such a large form, as well as illustrating his mastery of variation, counterpoint and unending ingenuity for innovative piano techniques. The composer's background and philosophies are discussed as well as the major impact made on his compositional style by both Percy Grainger and Ferruccio Busoni.