The Prelude and Fugue in D-sharp minor (often written enharmonically as E-flat minor), BWV 877, is the eighth work in the second book of Bach’s Well-Tempered Clavier. It is one of the most introspective and intricate pairs of the collection, marked by an antique expressiveness and a high degree of contrapuntal refinement. The prelude conveys a restrained melancholy, while the fugue, in four voices, unfolds as an elaborate and intellectually demanding composition distinguished by its contrapuntal variety and by the first appearance in The Well-Tempered Clavier of a theme combined with its own inversion. The prelude, set in a slow and solemn tempo, evokes a distinctly archaic atmosphere, with repeated-note figures contributing to its austere and plaintive character. Its construction relies heavily on imitation, giving the impression of a continuous dialogue between the voices. The piece is divided into two main sections, separated by a double bar, reflecting a balanced bipartite form. The first section, grounded in the tonic minor, establishes the expressive tone through clear motivic repetition and gentle modulation to the relative major (F-sharp major). The second section expands the harmonic range, visiting related keys such as A-sharp minor before concluding with a firm perfect cadence in the dominant. Despite its brevity, the prelude’s texture is dense and contrapuntally active, maintaining a consistent emotional gravity throughout. The fugue, in four voices, stands among the more intricate contrapuntal achievements of Book II. Its subject, introduced in the tonic minor, is severe in contour yet flexible enough to sustain extensive development. The fugue alternates between expositions and episodes characterized by imitative interplay—particularly between pairs of voices, a technique reminiscent of Corelli’s contrapuntal writing. As the work progresses, Bach heightens the complexity by introducing the inversion of the main theme, and the two forms are eventually combined, marking a notable point of synthesis and balance within the cycle. The overall texture is dense and tightly woven, demanding from both performer and listener a sustained concentration. The fugue closes with a sense of solemn inevitability, its introspective tone and structural mastery perfectly complementing the prelude’s antique melancholy.