Definition
The subject is the theme from which the whole fugue arises: it is stated alone at the beginning, then returns in all the voices and in different keys. A good subject is short, recognizable, clearly tonal (or modal) and suited to being combined with itself and with other lines. This entry focuses on how to build and analyze it; the entry on subject and answer deals with the relationship to the answer.
Anatomy
- Head: the first notes, the most characteristic gesture (a leap, a rhythm, a repeated note). It is the part that is recognized even in fragment, and that is used in stretti and episodes.
- Body and tail: the continuation, often by step and with shorter note values, leading to an arrival note. The tail supplies material for the episodes.
- End: the subject usually ends on the first or third degree (more rarely the fifth), or modulates to the dominant to prepare the answer.
- Range: generally within an octave, often within a sixth or a seventh, so that the answer fits in the same voice.
- Length: from one to four bars in keyboard fugues; longer in choral and organ fugues.
Types
| Type | Characteristics | Example |
|---|---|---|
| Subject in the old style | long note values, stepwise motion, characteristic leaps | Bach, BWV 849: C# B# E D# C# in half and whole notes |
| Subject with an initial tonic-dominant leap | requires a tonal answer | Art of Fugue: D A F D C# D E F |
| Modulating subject | ends on the dominant | the answer must return to the tonic |
| Rhythmic, instrumental subject | repeated notes, eighth and sixteenth notes, internal sequences | many fugues of the Well-Tempered Clavier |
| Chromatic subject | chromatic descent (lament) or diminished seventh leaps | Bach, Musical Offering (royal theme) |
| Arpeggiated subject | built on the notes of the chord | BWV 883: descending arpeggio and sixth leap |
How to evaluate a subject
- Can you sing it? If it cannot be sung, it will be hard to follow in the inner voices.
- Does it imply a clear harmony? The strong notes should suggest a simple progression (I–V–I, I–IV–V–I).
- Does it have internal rhythmic contrast? A slow part and a fast part make it easier to write the countersubject in contrast.
- Does it combine with itself? Try the stretto at the octave and at the fifth at different distances; a subject that admits stretti has more possibilities for development.
- Does it invert well? Try the inversion: if it remains melodic, you can use it in the counter-exposition.
- Is the head unmistakable? It is what the listener recognizes when the subject re-enters in the middle of the texture.
Teaching example in C major
Subject in half notes: C5 G4 A4 B4 C5 D5 C5.
- Head: descending leap of a fourth C–G, immediately filled in by step (G A B C).
- Climax: D5, then return to the tonic.
- Implied harmony: I – V – IV or ii – V – I.
- Stretto: the same subject, an octave lower and one bar later, forms sixth, tenth, third, third, octave: it works.
- Answer: since the second note is the dominant in a strong position, the tonal answer will respond to G with C.
Typical mistakes
- A subject that is too long or has too many ideas: the fugue becomes heavy.
- Excessive range: the answer leaves the register of the voice.
- Ambiguous or too rich implied harmony: every entry requires complicated reharmonizations.
- Uniform rhythm from beginning to end: the countersubject finds no room.
Modern application
- Soundtracks: a subject with a strong rhythmic head (repeated notes, leap of a fourth) works as an action motif and lends itself to canonic entries in the different sections.
- Pop and rock: a riff built like a subject (head + tail) can pass from guitar to bass to synth in imitation without losing identity.
- Choirs: subjects with long note values and a syllabic text in the head are the most effective for choral fugatos; fast notes go in the tail, on a vowel.
Related
Fugue: subject and answer, tonal answer and mutation, motivic analysis, stretto, Art of Fugue.