Habilitationschrift-Universität des Saarlandes, Saarbrücken. / Anhang, Quartetto per quinton, viola d'amore, viola da gamba e viola da basso P 061 (1906): p. 895-906. Includes bibliographical references (p. 869-893), work list (p. 829-867) and index.

This dissertation deals with Respighi's output for the organ which consists of the Three Preludes for organ solo, a Suite in G for strings and organ, two transcriptions (the Vitali Ciaccona, and a Suit by Bach), both for violin and organ, and various organ parts in the symphonic poems, operas, and orchestral works. If Respighi was not an innovator, he was at least creative in his use of the organ in his orchestral works. The organ was used primarily for color by adding depth, body, and novelty to the ever-growing orchestra. Respighi paid great attention to the smallest detail in his orchestrations, which were varied, delicate, and precise. Why did this interest in color and sonority not result in similar treatment of the organ in his music? The answer is suggested already in the description of the late romantic/orchestral organ. Its stops had lost their individuality, and they blended together in such a way that no particular color was distinguished. The though is not that Respighi's music, or the music of any other composer, caused the decline, but rather that the direction of organ-building in its search for modernity, machinery, and the industrial age, lost its identity, its characteristics personality and color, and lost in fact the very thing it was trying to achieve-- its autonomy.

Terra Mirabilis is a three-movement musical composition for symphony orchestra with piano solo inspired by natural landscapes photographed by the composer. The three movement composition and its corresponding landscapes portray three times of a day: early morning (I. The Mists), evening (II. Oceanus), and late night (III. Nocturne). Each chapter is devoted to the discussion of one movement, wherein overall concept and form are addressed, followed by detailed analyses of harmonic structure, motivic and thematic development, orchestration, and representational elements. As a complement to the score and the text, a CD-R audio recording of orchestral mock-ups accompanies this dissertation.