Lesson 1 · List A · Baroque
No. 6 of The Well-Tempered Clavier, Book II — the "chromatic fugue", and a prelude that sounds like a violin.
Johann Sebastian Bach never left Germany, had twenty children, and worked his whole life as a church and court musician. After he died, people thought he was old-fashioned. Today he is often called the greatest composer who ever lived.
1685 born in Eisenach → Weimar (organist) → Köthen 1717–23 (court music for a prince — that's where Book I was written) → Leipzig 1723–50 (Thomaskantor: music director of the town churches and the famous choir school).
① He is the end of the Baroque — the era is dated to his death in 1750.
② He wrote both books of the Well-Tempered Clavier (1722 and c. 1740).
③ His works are numbered BWV = Bach-Werke-Verzeichnis (Bach Works Catalogue), compiled by Wolfgang Schmieder in 1950 — ordered by type, not by date.
Handel and Domenico Scarlatti (born the same year, 1685), Telemann, Vivaldi, Rameau, Couperin. Fun fact: Bach never met Handel, though they were born the same year and lived in the same century.
The BWV catalogue puts all the cantatas first (BWV 1–224) and the keyboard works much later (BWV 846–893 are the Well-Tempered Clavier). So BWV 85 is a church cantata, but BWV 875 is your prelude & fugue. If an examiner asks how the catalogue works, that contrast is the perfect answer.
It's Bach's giant project: 48 preludes and fugues — two books of 24 — proving that you can write beautiful music in every single key.
Each book has 24 preludes & fugues, rising chromatically: C major, C minor, C♯ major, C♯ minor, D major, D minor… all the way to B minor. D minor is therefore No. 6.
Book I — finished 1722 at Köthen. Book II — compiled c. 1739–42 in Leipzig, about twenty years later. Your piece is from Book II, Bach's mature "modern" collection.
In Bach's Germany, Clavier meant any keyboard instrument with strings — harpsichord or clavichord — not the piano, which was brand new and almost unknown. So he wrote for a harpsichord-like sound.
Well-tempered means the instrument is tuned so all 24 keys work — but each key still sounds slightly different in colour. That is NOT the same as equal temperament, where every key sounds identical. (Equal temperament only became standard after Bach died.) Nobody knows exactly which tuning Bach used — but the whole point of the collection is showing off all 24 different key-colours. Say this and you sound like a real musician.
Put the music on while you read the next two sections. This recording follows a scrolling score, so you can watch the notes fly past.
The prelude is a moto perpetuo — "perpetual motion" — an unbroken stream of semiquavers that never stops, shared between the hands (watch for the hand-crossings).
Two halves, but no repeat signs (so it's a continuous binary, not a dance binary). Part I: D minor → A minor. Part II: A minor → back to D minor. Then a tiny coda (bars 57–61) over a held tonic note, ending in D major.
Bars 1–4 are played again at bars 5–8 with the two hands swapped (top becomes bottom). Then at bars 26–29 the whole thing returns transposed up a perfect fifth. Bach builds a whole movement from one idea turned upside-down and moved.
The repeated-pivot broken chords (from bar 2) are violin string-crossing — a trick called bariolage. Bach learned it by arranging Vivaldi's concertos. That's also why the hands cross over each other.
There is an earlier, shorter version of this prelude, catalogued BWV 875a. Bach lengthened it when he made Book II. The giveaway is the demisemiquaver flourishes at bars 22 and 24 — the only demisemiquavers in the whole piece, and almost certainly added later. Say "this little run is a later addition — Bach revised this prelude" and you've shown you really know the score.
A fugue is a musical conversation: one voice (or "part") starts a tune called the subject, then other voices copy it, one by one, while the music chatters on. Bach's fugue is only 27 bars — but it is one of the cleverest in the whole book.
The subject is exactly 2 bars and has two halves. First half: twelve fast triplet semiquavers (sextuplets) rising, mostly stepwise — light and dancing. Second half: a leap up to high D, then a slow chromatic descent in quavers back down. That falling chromatic line is the passus duriusculus — the Baroque "lament" figure, the same shape as the sad Crucifixus in Bach's B minor Mass. Two opposite feelings packed into one subject is a very "late-Bach", modern trick — and it's why the fugue is nicknamed the "chromatic fugue".
Alto (bar 1, alone) → Soprano (bar 3, with the answer) → a short codetta (bar 5) → Bass (bar 6). So: middle, top, bottom. The exposition ends at bar 8.
The subject starts D–E–F–G; the answer starts A–B♮–C–D. That B natural is the proof: it's an exact transposition up a fifth, with no adjustment. (A "tonal" answer would have tweaked a note to stay in the key.)
A second tune in even (duple) semiquavers that plays against the subject, creating a constant two-against-three ripple. It's a genuine countersubject, but Bach uses it freely rather than all the time.
The fugue uses stretto (voices entering on top of each other before the last one finishes) and inversion (the subject turned upside-down). There are four strettos, and the last one, at bar 25, is the climax: all three voices pile in half a bar apart, combining the subject right-way-up and upside-down at the same time. The key plan is deliberately tiny — only D minor (i), A minor (v) and G minor (iv) — because the excitement comes from the counterpoint, not from wandering keys. That's also why it can be so short.
Bach wrote no dynamics. Shape the music by how many voices are sounding and how tense the harmony is — think steps (terraces), not long romantic waves.
The harpsichord has no sustaining pedal, so Bach's counterpoint is written to be heard without it. On a modern piano, use only tiny "touch" pedals to connect what the hand can't reach — never enough to blur the voices.
The Baroque rule: a trill begins on the note above, on the beat. (Bach's own chart — the Explication of 1720 — and his son C. P. E. Bach's book of 1753 both say so.) Very few ornaments are written in this pair.
Differentiate the subject's two halves with touch, not dynamics: play the rising sextuplets smooth and even, then let the chromatic quavers be slightly heavier and more "spoken". Then use exactly the same articulation every single time the subject appears — that consistency is what keeps the tune audible in every register.
In the exam, a strong answer has four moves: Name it → Place it → Contextualise it → Land it on a decision. Here's the shape, using the fugue subject.
"The subject is exactly two bars and it has two characters. The first half is twelve rising triplet semiquavers — light and dancing — and the second half leaps up to high D and descends chromatically through a fourth, which is the passus duriusculus, the Baroque lament figure. It's a late-Bach trait to pack two affects into one subject, and it's why this is called the chromatic fugue. So I play the semiquavers smooth and the chromatic quavers more weighted and speaking — and I keep that exactly the same for every entry, so the subject stays clear wherever it appears."
How is The Well-Tempered Clavier organised?
Two books of 24 preludes & fugues — one pair in every major and minor key, rising chromatically (C major, C minor, C♯ major…). So D minor is No. 6.
Is the fugue's answer real or tonal — and which note proves it?
Real. The answer starts A–B♮–C–D; the B natural shows it's an exact transposition up a fifth, not adjusted to stay in the key.
Where is the fugue's climax, and what happens there?
Bar 25 — a three-voice stretto in the tonic, combining the subject right-way-up and inverted, half a bar apart.