Bach J S Prelude and Fugue in C sharp Minor from Well-Tempered Klavier Book 1, BWV 849 (1721) ; Marc

This site features selections from a collection of two books of preludes and fugues entitled “The Well-Tempered Klavier”: (1) Prelude in D from Book 2; (2) Prelude and Fugue in F-sharp minor from Book 2; (3) Prelude and Fugue in C-sharp minor from Book 1. The Well-Tempered Klavier is a collection of prelude and fugue sets written in each of the twelve keys of the chromatic scale. They were written to commemorate the advent of the modern keyboard tuning known as “equal temperament,” which divides the octave into twelve equally spaced half-steps. Prior to this tuning innovation, the keys with the most sharps and flats were not used because they sounded horribly out of tune. The first book of the Well-Tempered Klavier features the earliest historical use of key signatures with 5 and 6 sharps or flats. The Well-Tempered Klavier as a whole is organized into two books, each containing 24 sets of preludes and fugues, in the major and minor key on each half step of the octave. The first book was published in 1721, the second was completed around 1740. The fugues of the first book feature rigorous counterpoint with short subjects in rhythmically tight imitation. The second book was pulled together later from various prelude and fugue sets written over the two decades between the collections. As such, the second book shows greater freedom and variety in the counterpoint and in stylistic features. The fugues of both sets generally involve either 3 or 4 voices stating an opening subject in imitation. The fugues follow strict rules governing intervals, resolution of dissonances, voice-leading, melodic contour, and rhythmic relations. The greater variety in stylistic character in the fugues of the second book is partly attributable to longer subjects and longer episodes between the imitative entrances, and partly to a broader palette of contrapuntal devices. The fugues in both books make use of “inversion”, where the subject is imitated upside down, with rising melodic intervals turned into roughly the same descending interval in a mirror image. Use of “diminution” and “augmentation”, the fugue subject in double time or half time, are very rare in the first book, but quite frequent in the second. The use of these devices enables the fugues of the second book to express a wider range of emotions and feeling than in the first book. Both fugues featured on this site also exemplify a contrapuntal style older than fugue itself, known as “ricercare,” in which additional subjects or countersubjects are introduced imitatively during the course of the work. The F-sharp minor fugue from WTK Book 2 is a ricercare fugue in 3 voices. The Fugue in C-sharp minor from the first book is an exceptional ricercare fugue in 5 voices, in which a lyrical opening subject is supplemented midway through by an energetic countersubject, to give the work a solemn effect with a dramatic buildup.