The standard string techniques cover perhaps half of what string instruments can do. The extended palette — exploited fully only in the twentieth and twenty-first centuries — transforms the string section from a singing voice into an entire acoustic laboratory.
BEYOND ARCO AND PIZZICATO
The standard orchestral string techniques — arco (bowed), pizzicato (plucked), and tremolo — form the foundation of string writing. But the extended techniques available on string instruments dramatically expand the palette, and understanding them is essential for anyone writing music after 1950.
SUL PONTICELLO
Bowing very close to the bridge increases the relative strength of the upper harmonics, creating a glassy, ethereal, slightly metallic tone. Sul ponticello (literally "on the bridge") is notated in the score and reversed by the instruction "normale" or "ord." (ordinario).
The effect ranges from barely perceptible (a slight edge to the tone) to extreme (a ghostly, almost electronic whisper). Bernard Herrmann's Psycho uses sul ponticello strings to create the shower scene's horror. Ligeti's string quartets use it for extended passages of spectral texture.
SUL TASTO
The opposite of sul ponticello — bowing over or near the fingerboard, reducing the high harmonics and creating a softer, flute-like tone. Useful for quiet, veiled passages where the string section needs to blend without edge.
COL LEGNO
Striking the string with the stick of the bow rather than the hair produces a dry, clacking, pitched sound. Gustav Holst uses it in the "Mars" movement of "The Planets" for the relentless mechanical rhythm. Bartók and Crumb use it for skeletal, percussive effects.
HARMONICS
Harmonics are the most exploited of the extended string techniques in orchestral music:
Natural harmonics: touching the string lightly at a nodal point (halfway, one-third, etc. of the string length) produces a flageolet-like tone one or two octaves above the open string. Natural harmonics are reliable and consistent.
Artificial harmonics: stopping the string with one finger and lightly touching a point above with another finger produces harmonics from any starting pitch. More flexible than natural harmonics but require care in writing.
The harmonic's characteristic sound is pure, glassy, and very high — resembling a flute in its most extreme upper register. Ravel, Debussy, and Ligeti use harmonics to create the impression of sound dissolving into overtone.
SNAP PIZZICATO (BARTÓK PIZZICATO)
The string is pulled sharply away from the fingerboard so that it snaps back against the wood. This creates a loud, aggressive, rhythmic crack — notated with a circle above the note. Associated primarily with Bartók (hence the name), it appears throughout his string quartets and the Concerto for Orchestra.
SCORDATURA
Tuning one or more strings of an instrument to a non-standard pitch. Scordatura was used extensively in the Baroque period (Biber's Mystery Sonatas, Paganini's Caprice No. 24) and revived by twentieth-century composers. It extends the instrument's range or creates unusual resonances when open strings are used.
Mahler's Symphony No. 4 requires the concertmaster to tune all strings a whole tone higher than normal — the resulting tone is more brilliant and slightly harsh, appropriate for the movement's death-dance character.
MULTIPHONICS AND BOW PRESSURE EFFECTS
Extreme bow pressure can force the string to produce double frequencies — "growling" multiphonics that sound like two or more pitches simultaneously. Notated variously; common in avant-garde chamber music and used for maximum intensity in climactic passages.
MICROTONES AND QUARTER-TONES
String instruments can play any pitch — they are not limited to the equally-tempered scale. This makes them uniquely capable of producing microtonal inflections (pitches between the semitones of the Western scale). Scelsi, Xenakis, and Lachenmann exploit this extensively.
BOWING ON UNUSUAL PARTS OF THE INSTRUMENT
The string body has many resonant surfaces beyond the strings themselves, and contemporary composers exploit them. Bowing on the bridge (literally on the bridge wood, not just close to it) produces an almost pitchless scraping sound. Bowing on the tailpiece produces dry clacking. Bowing behind the bridge (between the bridge and tailpiece) produces extremely high, glassy pitches with a metallic edge — the strings on that side of the bridge are very short. Bowing on the body of the instrument is also possible, producing percussive sounds. Helmut Lachenmann's compositions ("Pression" for solo cello, 1969) systematically explore these "noise-music" possibilities, turning the cello into a percussion and air-noise instrument as much as a pitched string instrument.
GLISSANDO TECHNIQUES
String glissandos — sliding from one pitch to another along the same string — are notated with a line connecting the two notes. They can be slow (audibly searching) or fast (a smear of sound). A glissando between two harmonics produces a strange whistling effect of changing pitch and timbre simultaneously. Glissandos on multiple strings (parallel glissandos) produce a sheet of pitch-bending sound — Penderecki's "Threnody" uses sheets of glissandos at multiple registers.
TREMOLOS, MEASURED AND UNMEASURED
- The standard tremolo (rapid bow movement on a single pitch) can be notated as:
- Unmeasured tremolo (with three slashes through the stem): as fast as the player can manage.
- Measured tremolo: written-out subdivisions of a longer note (e.g., 16th notes over a half note), played as written.
- Bowed tremolo: produced by bow alternation.
- Fingered tremolo: rapid alternation between two pitches on the same string, like a trill but with the bow sustained — actually a special kind of trill.
Tremolos provide the orchestra's most common expression of tension and agitation. The contrast between a sustained, calm passage and a tremolo passage on the same pitches is one of the simplest dramatic devices available.
CIRCULAR BOWING AND OTHER MOTOR TECHNIQUES
Some contemporary string techniques involve unusual bow motions: circular bowing (the bow moves in a circle, contacting the string with rotation rather than linear movement); bow tremolo with extreme pressure (producing a scratch tone); jeté or ricochet (the bow is thrown onto the string and allowed to bounce, producing a series of rapid notes from a single arm motion); and rebote (Spanish for "rebound," similar to ricochet). Each produces a different texture and is notated with conventional symbols or text instructions in the score.
PIZZICATO VARIATIONS
Beyond standard pizzicato, the techniques include:
Bartók pizzicato (snap pizzicato): pulling the string sharply away from the fingerboard so it snaps back; notated with a circle above the note. Left-hand pizzicato: the left hand plucks the string while the right hand continues bowing or holds the bow; notated with a "+" above the note (different from stopped horn's "+"). Pizzicato glissando: pluck the string and then slide the left finger along it. Buzz pizzicato: pluck with a fingernail at the bridge or end of the string for a buzzing quality. Dampened pizzicato: pluck with the left hand laying lightly on the string, producing an almost pitchless thud.
PREPARED STRINGS
Some twentieth-century composers — Crumb, Cage — extended string instruments through preparation: clipping objects to the strings, weaving paper through them, or placing tape on the fingerboard. The results modify timbre dramatically but are typically too unpredictable for orchestral use. They appear primarily in chamber and solo music.
THE LATERAL BOW TECHNIQUES OF LACHENMANN
Helmut Lachenmann's category of "musique concrète instrumentale" exploits noises produced by playing technique itself — the friction of bow against string, the sound of fingers moving on the fingerboard, the percussion of the bow against the wood. His works "Gran Torso" (string quartet, 1971), "Pression" (cello, 1969), and "Mouvement (— vor der Erstarrung)" (chamber ensemble, 1984) catalog these techniques.
NOTATION OF EXTENDED TECHNIQUES
Extended techniques require careful notation. Standard conventions are gradually emerging, though publishers and composers still differ. Useful references include Patricia and Allen Strange's "The Contemporary Violin" (University of California Press, 2001), the notation guides from Universal Edition and Boosey & Hawkes, and Kurt Stone's "Music Notation in the Twentieth Century" (W. W. Norton, 1980). For each extended technique, a composer should include either a footnote, a performance note at the front of the score, or both — assuming the players will need to learn or refresh techniques that are not standard repertoire.
EXERCISE: EXTENDED TECHNIQUE LISTENING
Find a recording of Ligeti's "Études" for string quartet and Penderecki's "Threnody for the Victims of Hiroshima." For each, identify three specific extended techniques by ear. Use the scores (available on IMSLP for Penderecki; publisher edition for Ligeti) to confirm your identifications. Note the emotional effect of each technique. As a second exercise, listen to Lachenmann's "Pression" for solo cello and try to identify how many distinct sounds a single cello can produce when extended techniques are systematically applied.