Definition
A stretto occurs when a voice begins the subject (or the answer) before the previous voice has finished it: the entries overlap and the tension increases. The stretto is usually reserved for the final part of the fugue, but it can appear anywhere; a fugue that starts out with overlapping entries is called a close fugue (fuga stretta).
Parameters of a stretto
- Interval of the second entry: unison, octave, fifth, fourth, others.
- Distance: after how many beats the second voice enters. The shorter it is, the tighter the stretto.
- Number of voices involved: two, three or all.
- Form of the subject: direct, inverted, augmented, diminished (strettos by contrary motion or by augmentation).
How to check a stretto (a paper test)
- Write the subject on one staff.
- Below it, copy it at the desired interval, shifted by the chosen distance.
- Check the intervals on the strong beats: they must be consonances or correctly treated dissonances (passing tones, suspensions).
- Check for parallel fifths and octaves.
- If it does not work, try another distance or another interval, or accept small changes in the tail of the first voice (the stretto requires only the overlapping part to be exact).
- Note down all the possible strettos before writing the fugue: they determine the plan of the final part.
Verified example in C major
Subject in half notes: C5 G4 A4 B4 C5 D5 C5.
Second entry at the lower octave, after one bar (two half notes): C4 G3 A3 B3 C4 D4 C4.
Intervals on the beats where the voices overlap: A4 over C4 a sixth, B4 over G3 a tenth, C5 over A3 a third (minor tenth), D5 over B3 a third, C5 over C4 an octave. All consonant, with no parallels: the stretto at the octave at a distance of one bar works.
Types
- Simple stretto: two voices.
- Multi-voice stretto: three or four entries at equal distances, often with an exact canon for a few bars.
- Grand stretto (stretto maestrale): all the voices enter in stretto and complete the subject in full.
- Stretto by contrary motion: one voice direct, one inverted.
- Stretto by augmentation: the subject in doubled values against itself in normal values (The Art of Fugue, Contrapunctus 7).
- False stretto (false entry): the second voice begins the head but does not continue.
Examples in the repertoire
- The Well-Tempered Clavier I, Fugue in C major BWV 846: a fugue built almost entirely on strettos, with a four-voice canon in bars 14–15.
- Fugue in C# minor BWV 849: the subject in stretto at bar 55 and, more densely, in bars 94–99.
- The Art of Fugue, Contrapunctus 5–7: strettos with the subject direct and inverted, augmented and diminished.
- Mass in B minor: the Gratias agimus tibi is a fugue in which the exposition itself proceeds in stretto.
Typical mistakes
- Inserting a stretto without having checked it: the final part of the fugue gets stuck.
- Strettos with entries in the same register: the voices get confused.
- Changing the subject so much to make the stretto work that it is no longer recognizable.
- Putting the tightest stretto at the beginning: the fugue has nowhere left to build.
Modern application
- Film scores: strettos of a motif between brass and strings are the natural climax before the final cadence; they increase the energy without raising the tempo.
- Electronic production: duplicating a phrase and shifting it by a beat or a bar into another octave (with the necessary corrections) creates strettos that give density to endings.
- Choirs: choral stretto works if the subject has a clear syllabic head; closely spaced entries on different words make the text incomprehensible, so it is best to use the same word.
Related topics
Fugue: stretto, pedal and devices, canon, fugue subject, analysis of the Fugue BWV 846, The Art of Fugue.