The contrapuntally constructed Prelude (Allegretto, completed on November 2, 1950) is permeated throughout by sharp dotted rhythms. This rhythm, the key of B minor, and the use of diminished seventh chords imbue the music with strong emotion and a dramatic impression.

The descending melodic figure and pianissimo at the end of the Prelude lead to the dark, abyss-gazing subject of the Fugue (four voices, Moderato, completed on November 9, 1950). The subject, played in the lowest voice, is divided into a long-breathed first half consisting of half notes and quarter notes, and a second half with intricate figures of eighth notes and sixteenth notes. The countersubject is also spun out from similar elements. The complex and interwoven texture of the entire piece is generated by these elements.