Ernst Krenek (1900-1991) ranks among the most prolific composers of serial music in the twentieth century. Beginning in the 1930s in Vienna, he adopted the twelve-tone technique and, after emigrating to the United States in 1938, continued to refine his approach, eventually embracing total serialism in the 1950s.

Alongside his compositions, Krenek authored theoretical writings on serialism, arguing for its historical necessity as a logical evolution of musical material. Both his compositional practice and his theoretical reflections converge in Exercises of a Late Hour (1967), a work for chamber orchestra and electronic tape. This paper examines the piece as a lens through which to understand Krenek's trajectory within serialism — tracing phases from twelve-tone technique through strict serial structures of rhythm, meter, and tempo — to their eventual dissolution into what Krenek defined as the dialectic of serialism: "Total predetermination produces the image of total chaos."

The analysis will examine the work from multiple perspectives: serial procedures, timbre, and density of musical events as these relate to the interaction between the chamber orchestra and preproduced tape. I argue that Exercises of a Late Hour represents the culmination of Kreneks commitment to the strict predetermination of musical material and its dialectical counterpart: chance. The electronic component of the work signals a move toward indeterminacy, while the orchestral writing mostly retains the rigor of serial organization. The final section achieves an "apotheotic" resolution, merging electronic and instrumental sound to eliminate any indication of serial determinism — realizing a work that is, ultimately, "music about music."