The work's title combines three words: horizontal, diagonal, and vertical, representing three types of musical narrative that make up its form.
Notwithstanding a developing orchestral timbre and texture, the initial fragment is harmonically static. Pitches oscillate between B♭ and B. The listener's may perceive the narrative of that section as a motionless, horizontal line. After several minutes comes a gradual development, with the plot unfolding simultaneously on several levels. The harmony changes in a fluid way, one articulation leading into another, and so forth. The resulting imitations and counterpoints bring to mind a diagonal structure. Many threads intertwine, creating complex skews. Musical events become swifter, the plot proceeding to another episode where the action is often interrupted as if by vertical lines, symbolising the verticality indicated in the work's title.
After this section, we go back to the horizontal-like static narrative. As before in the introduction, a sonoristic section with a horizontal narrative is followed by a diagonal section, then by another episode full of sudden, vertical turns.
The work's ending is built in a similar fashion. Here, three instruments play a key role: the accordion, violin, and cello, whose dialogues are violently interrupted by the orchestra. From the beginning of the composition, musicians playing those instruments play semi-soloistic, virtuoso parts, rising somewhat above the ensemble, only to reassume the role of accompanists and blend into the orchestral apparatus. Because of this treatment, we can never be sure if they are truly soloists, as their parts rarely come to the fore.