Fugue Form · Theory

Fugue Musical Form Imitation Sonata Form Pedal Point

This entry divides the labour with fugue as a technique clearly:

T6's "fugue" covers the writing (how the subject enters and interweaves); this entry covers the structure — how that writing is arranged into sections across a whole piece.

The three-section logic

Section	Content	Common devices
exposition	voices enter in turn, stating the subject	subject → answer (dominant) → subject → answer
middle	the subject keeps appearing while the tonality keeps moving	episodes (subject fragments pushed by sequence, see [[concept:sequence
final	the subject returns to the tonic and closes	stretto (overlapping entries) + pedal point (see [[concept:pedal-point

The sections are divided on different grounds from sonata form: sonata form relies on tonal contrast (the second subject in the dominant); a fugue relies on the density of entries and tonal distance — there is no "second subject", only one subject recurring in different keys.

The comparison with sonata form

Both belong to the "exposition-development-return" family, but with different mechanisms:

	Sonata form	Fugue form
What supplies contrast	two subjects and two keys	one subject and varying density/tonal distance
Means of "development"	taking the material apart (fragmentation)	transposing the subject (entries in many keys) plus episodes
Sign of return	the second subject returns to the tonic (tonal unity)	the subject returns to the tonic, often in stretto
Means of closing	cadence	pedal point plus cadence

In one line: sonata form builds tension from two things; a fugue builds it from one thing in changing circumstances.

Diagram: what divides the sections

Listen: return and close

Use progression on a departure-and-return span. A fugue's closing feels the same way — the subject coming home after drifting through many keys is what marks the structure complete.

Common misconceptions

"A fugue is a fixed form with a set number of sections." The sectional logic exists, but **the number and

length of sections are highly free**. A short two-voice fugue may be an exposition plus a single episode.

"A fugue has no sections." The opposite: it has a clear three-part logic — its divisions rest on **the density

of entries** rather than on cadences.

"A fugue must have four voices." Two to five all occur (see fugue).
"Fugue form is sonata form in polyphony." Same family, different mechanism: one relies on tonal contrast, the

other on the layering of one subject. :::

Listen in the library

Chromatic Fantasia and Fugue in D Minor, BWV 903C111:25Bach's Chromatic Fantasia and Fugue — the entries and their later development are clearly layered and can be followed section by sectionDetailsPreludes and Fugues for Piano, Op.87: No.23 in F majorC15:36Shostakovich's Preludes and Fugues Op.87 — twentieth-century fugues, showing how the traditional sectional logic persistsDetailsFugue in A minorC12:10A fugue by Chopin — a Romantic fugue, useful for comparing how the subject is handledDetails

All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).

Sources

赋格的段落逻辑（呈示段 / 中间段 / 结束段）与各段常见手法，属曲式分析通则
与奏鸣曲式的对照（赋格不依赖调性对比而依赖素材层叠），为通行表述

Used for fact-checking only; all prose is original.

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