Bowed string instrument extended technique

String instruments are capable of producing a variety of extended technique sounds. These alternative playing techniques have been used extensively since the 20th century. Particularly famous examples of string instrument extended technique can be found in the music of Krzysztof Penderecki (particularly his Threnody to the Victims of Hiroshima), Witold Lutosławski, George Crumb, and Helmut Lachenmann.

Bowing the body of a string instrument (which can include bowing the sound box, neck, tuning pegs, or scroll) produces a quiet sound whose amplitude differs according to the place bowed, bow pressure and bow speed. At most the sound is a whisper of the bow hair moving over the wood. A good example of this technique in a musical work is Helmut Lachenmann’s Toccatina, a piece written in 1986 for solo violin which uses many extended techniques.

Bowing on the bridge produces two different effects depending on how it is done. If it is done while the performer is in normal playing position, the sound produced is quiet, whispery and a bit squeaky. This method could more properly be called 'bowing over the bridge', since the bow hair is usually still in contact with the strings. Sul ponticello (bowing near the bridge) is a similar, more common technique.

The other method involves the performer holding the instrument in their lap, placing the bow parallel to the instrument and firmly dragging it across the side of the bridge. In this case the sound is loud, high pitched and squeaky. An example of this playing technique can be found in Gérard Grisey’s Vortex Temporum (1995). Helmut Lachenmann often uses a soft version of this technique, creating a quiet, white-noise-like sound.

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