Ex. 12-1: Fugue (edited fragment)

No. 8 from Book I of Bach's Well-Tempered Clavier, compiled around 1722. Its prelude and fugue are written in different keys: the prelude in E-flat minor (six flats), the fugue in D-sharp minor (six sharps) — the same pitch, spelled two ways.

Scholars believe the fugue was first written in D minor, then moved up a half step to D-sharp minor. Writing it in D-sharp minor let Bach keep every note in the same place and just add sharps, instead of rewriting the whole piece in E-flat minor. One clue is a high C-sharp in bar 16 — a note higher than the keyboards of Bach's day could reach, as if it had been pushed up from a lower original. This odd spelling bothered later editors: Czerny's popular 19th-century edition simply printed the fugue in E-flat minor.

The fugue itself is a showcase of craft — three voices built on a single theme. Bach turns the theme upside down (inversion) and stretches it to double its length (augmentation), fitting these transformations together like a puzzle. Bach's famous late work, The Art of Fugue, is full of techniques like these.

Wagner's wife Cosima recorded his reaction to this fugue: "Richard considers it the most remarkable piece; extremely artful and yet so full of atmosphere. 'What strettos, what augmentations, and what accents.' For him, it is the very essence of fugue."

Mozart later arranged this fugue for string trio — violin, viola, and cello — adding a new prelude of his own, though scholars debate how much of the work is really his.

Note: This version is an edited fragment adapted for sight-singing practice.

From the album Bach: The Well-Tempered Clavier, Book I by Ramin Bahrami (2018)
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