Orchestration: PART 3 - Theory (Strings)

LESSON THREE

THE STRING QUINTET

The quintet of string instruments that are the largest grouping of instruments in the orchestra are also the most homogenous in timbre. This comes from their common ancestors and means of producing sound.

String instruments are at once the easiest grouping for which to write, and the hardest for which to write perfectly idiomatically. Poorly orchestrated music for strings still sounds good because of the nature of the string sound. However, our goal here is to achieve a superior level of orchestration. Again, as for the brass instruments, a good book on instrumentation is essential for learning the huge variety of string techniques that are available to the composer/orchestrator. The limited scope of this online lesson will not allow us to go into quite as much detail, however we will try and cover some of the basic techniques that are available.

If we thought that the clarinet was the Sybil of woodwinds, we are in for a surprise, as the strings represent an entirely new level of musical schizophrenia.

STRING TECHNIQUES

Bowed techniques
Sound on a string instrument is achieved through the vibrations caused by the rubbing of rosin-covered horse-hair against the strings of the instrument. Generally, the bow is moved across the string at a point mid-way between the end of the fingerboard and the bridge. This produces the “normal” sound of the string instrument.

By moving the bow onto the fingerboard, one gets the “sul tasto” (in French “sur la touche”) effect. The bow here cuts closer into the vibration of the string, created an almost muted effect.

Moving the bow closer to, or even right across, the bridge gives the “sul ponticello” effect. Amateurs of horror movies recognize this effect from its over-use in B-grade film scores. The effect is extremely colourful, and easily over-done. Sul ponticello is often accompanied by another bowing effect: tremolo. This is the rapid (unmeasured) movement of the bow, back and forth, to create a sort of trembling effect.

Yet another effect that is achieved with the bow, but not in the traditional manner of using it is “col legno”, or “with the wood”. Here the bow is turned upside down so that the wooden part rather than the hairs strikes the strings. The effect is very percussive, though not terribly loud (remember the opening of “Mars” in Holst’s suite “The Planets”). The intonation of strings col legno is indistinct, so it is unusual to ask for a specific melody to be played thus. While col legno is a “struck” effect with the bow, some composers (notably Mahler) have actually asked string players to bow across the strings with the wooden part of the bow. The effect is extremely light, and at least in my opinion, of dubious value.


Plucked techniques
String players can use fingers to play the strings as well. This is called pizzicato. Basically, they pluck the strings like a harp. In soft dynamics the effect can be very rich and light, while in loud dynamics it is heavily percussive, especially if the string is allowed to strike the fingerboard. The latter effect is often called a “Bartok pizz.”, and can be indicated by a little circle over the note with a tiny vertical slash in the top.

When the composer asks a string player to change bowing techniques, or to use the fingers and pluck strings, the effect is indicated in the score with a text expression. To have the musician return to “normal” string technique, a new expression is added. When pizzicato is needed, simply writing “pizz.” will suffice. To return to bowed strings, indicate the return with “arco”. For other effects, the return to normal bowing technique is indicated with the expression “ord.” (for “ordinario”).

You should think of pizzicato strings as a different instrument when considering tone weight and timbre. Pizzicato will not “blend” with other string sounds as easily as some of the other effects due to its percussive nature. The same is true of col legno.