The purpose of this study is to encourage research in contemporary organ music, which has been considerably neglected. The period 1945 to 1965 has been taken as the scope of this study. Only solo organ music has been selected, although a considerable quantity of music for organ and other instruments exists. Determining the stylistic trends present in the organ literature involved has necessitated an analytical search into organ music of the following countries: Canada, England, France, Germany, Latin America, and the United States. The greatest activity in organ music since 1945 has occurred in Germany. Thus, this study emphasizes German composers more than any other. Musical analysis in this study stresses compositional unifying devices and emphasizes unusual rather than common technical elements. The author avoids bar-by-bar analysis but stresses a survey of compositional practices. If a germ motive or Grundgestalt occurs, the writer determines its importance to the formal and stylistic characteristics of the music. Special attention has been given to permutation, interversion, polyharmonic and polychordal functions, as well as pandiatonic, polymodal, and polytonal textures. Unusual features of registration have been discussed, along with the composer's idiomatic treatment of the organ. Text painting has been mentioned wherever present. The writer has found that a composer's style is the result of technical and formal compositional devices, in the same way that a writer's style is the result of his use of elements such as grammar and diction. Thus, form and style are inseparable, but one is the result of the other. Background influences have led to the study's organization, having shown that this music embraces three stylistic divisions: neo-Baroque, neo-Romantic, and Syncretistic. The first two categories include, respectively, the eclectic practices of composers who have followed eighteenth-century German and nineteenth-century French influences, while the third category represents composers who have emulated more advanced twentieth-century composers. The term Syncretistic describes the practices of composers who use various serial techniques in styles that avoid eclecticism and neoclassicism. The author avoids entitling the third category serial, for serial indicates procedure rather than style. The composers chosen are representatives of the three stylistic categories in question. They were selected only after investigating many other composers. Their selection does not imply musical evaluations. These composers have not received proper recognition and their music has been performed very seldom. The author has not discussed music already well-known. The composers and compositions are now given, as they appear in the three chapter divisions: neo-Baroque works: Joseph Ahrens, Triptychon uber B-A-C-H; Richard Arnell, Second Sonata; Willy Burkhard, Choral-Triptychon; Harald Genzmer, 1963 Sonata; Alberto Ginastera, Toccata, Villancico, y Fuga; Ernst Pepping, Three Fugues on B-A-C-H; Hermann Schroeder, Veni Creator Spiritus; Gerhard Wuensch, Sonata Breve. Neo-Romantic: Samuel Adler, Toccata-RecitationPostlude; Henk Badings, Prelude and Fugue IV; Jeanne Demessieux, Triptyque; Harald Genzmer, Tripartita in F; Otto Luening, Fantasia; Jan Mul, Choral Joyeux; Daniel Pinkham, Suite. Syncretistic works: Joseph Ahrens, Verwandlungen I; Helmut Bornefeld, 1955 Partita; Johann David, Partita on B-A-C-H; Siegfried Reda, Preludium-Fuge-Quadruplum, 1960 Senate, and Triptychon. This investigation has revealed that organ music of the middle sixties has not yet embraced experimentalism in aleatory and electronics, characteristic of contemporary music in other fields. The current stylistic streams in organ music depart widely from current activities in other music. Thus, this study should be of importance to those interested in contemporary trends and of special value to those who perform and teach organ music. This study also indicates a vast area still unexplored by organ composers, including aleatory, experimental activities of many types, and ethnic musical sources.