In Austro-German music of the late nineteenth century, the landscape of extreme musical slowness took on a powerful, new identity. This dissertation examines this phenomenon through a series of case studies focusing on works of Bruckner, Wagner, and Mahler. Combining close musical analysis with a consideration of reception discourse and contemporary aesthetic theory, this work sheds new light on a largely overlooked Adagio "rhetoric." This vocabulary of musical slowness shapes and responds to habits of listening and musical comprehension in the last decades of the century.

Departing from tradition, the Adagio of Bruckner's Seventh Symphony was of unprecedented importance in characterizing the complete work for its early audiences. While this was typical for chamber works, slow movements of symphonies were not regularly accorded such prominence. The pivotal role of the Adagio within Bruckner's symphony signals the arrival of a rich moment in nineteenth-century music. Symphonic aesthetics are re-defined, and listening habits associated with the intimate realm of chamber music are now aligned with the public genre of the symphony. In discussing this work, the concept of the "lyric" provides a fertile context by which to identify and analyze the particular elements of Bruckner's Adagio style.

In Wagner's Parsifal, the topic of slowness is especially complex. As much as the work itself, its performance history has influenced the understanding of tempo in the piece. Wagner's own opinions on tempo illuminate those passages in Parsifal that are markedly slow. An analysis of the Act I Prelude and Grail Scene suggests points of intersection between Wagner's slow tempi and the vocabulary of Adagio style. Issues of form, timbre, rhythm, and melodic design challenge the perception of goal-oriented musical time by emphasizing the individuality of discrete moments.

In Mahler's Third Symphony, the final movement represents a continuation of these same trends. Satisfying the requirements for a solemn Adagio and a grand Finale, this movement echoes and expands the elements of Adagio rhetoric identified in Bruckner and Wagner. Trends in reception suggest that Mahler's identity as composer and conductor was a primary influence in defining the public and historical image of the piece.