Science Fair Project Encyclopedia
- For other uses of the word, see Viola (disambiguation).
The form of the viola
The viola's four strings are tuned in fifths: the C an octave below middle C is the lowest, with G, D and A above it. This tuning is exactly one fifth below the violin and one octave above the cello.
Playing the viola
The viola is played by using the right hand to draw the bow at right angles across one of the strings, near the bridge, causing the string to vibrate. Pitch is controlled by selecting the string that the bow contacts (by altering the vertical angle of the bow), and by regulating the sounding length of that string by pressing it down onto the fingerboard with one of the fingers of the left hand.
Fingering and positions
The placement of the fingers on the strings invokes no physical aid like frets; the player must achieve the correct position from skill alone, or else the instrument will sound out of tune. Violists practice long hours partly to train their fingers to land in the right places, and partly to cultivate the ability to correct the pitch very rapidly as it is played.
The fingers are conventionally numbered "first" (index) through "fourth" (little finger). The digits 1-4 sometimes appear over the notes in viola music, especially in instructional editions, to indicate the finger to be used.
For the beginning player, the highest note available on a viola is made by pressing the fourth finger down on the A-string, sounding a high E. However this is only the highest note in so-called first position, which is taught to beginners first. A higher note can be achieved by sliding the hand up the neck of the viola (towards the player's face) and pressing the fingers down at this new position. Thus, for example, in first position, the first finger placed on the A string gives a B. Pressing the first finger instead on second finger placement is called second position. Third position is achieved when the first finger presses down on the third finger placement, and so on. The upper limit of the viola's range is largely determined by the skill of the player. A good player can easily play more than two octaves on a single string, and four octaves on the instrument as a whole.
Violists often change positions on the lower strings even though this seems unnecessary. Often, this is done to handle a musical passage which would otherwise require fast switching of strings. It is also done to produce a particular timbre: a viola note will sound different depending on what string is used to play it.
A special timbre results from playing a note without touching its string with a finger, thus sounding the lowest note on that string. Such a note is said to played on an open string. Open string notes (C, G, D, A) have a very distinct sound resulting from absence of the damping action of a finger, and from the fact that vibrato (see below) is impossible. Other than low C (which can be played in no other way), open strings are usually selected for special effects.
One striking effect that employs open strings is bariolage. Here, the player fingers the same note of an open string (necessarily G, D, or A) on the immediately lower string, then moves the bow with a rapid snake-like motion that causes it to touch the fingered string and the open string alternatingly. The same pitch is thus sounded, but the different timbres of an open string vs. a fingered string produce an audible rhythmic pulsation. Bariolage was a favorite device of Joseph Haydn, who used it for example in his string quartet Opus 50 no. 6, and in the "Farewell" Symphony.
Double stopping is playing two strings simultaneously, producing a chord. This is much harder than normal single-string playing as more than one finger has to be accurately placed on two different strings simultaneously. Sometimes moving to a higher position is necessary in order for it to be physically possible for the fingers to be placed in the correct places. Double stopping is also used to mean playing on three or all four strings at once, although such practices are more properly called triple or quadruple stopping. Collectively, double, triple and quadruple stopping is called multiple stopping.
See Double stop for general information about the techniques of double stopping and bowing.
When a note is marked pizzicato in the written music, it is played by plucking the string with a finger rather than with the bow. For details of how pizzicato notes are played, see "Pizzicato".
Vibrato is a very common device used by violists which causes the pitch of a note to vary up and down quickly. This is achieved by moving the finger pressing on the string slightly forwards and backwards. Vibrato is often perceived to create a more emotional sound, and it is employed heavily in music of the Romantic era. There are several different styles of vibrato ranging from the use of just the fingers, to the use of the wrist or even the whole forearm. These produce different effects and are favoured by different players for different styles of music. Some styles of music use little or no vibrato at all.
It is often thought that vibrato can partially disguise an out of tune note, the intuitive idea being that the ear should not be able track pitch as accurately when it is moving up and down. However, recent experimental work finds no such effect: the human ear detects the mean frequency of a vibrato note just as accurately as it detects a non-undulating pitch. It is not necessarily the case that results obtained under careful experimental conditions will carry over to real-life playing, and there is at least some evidence that vibrato may be able to disguise mistuning at faster tempos. Nevertheless, it now appears that individuals learning to play the viola are well advised never to suppose that using vibrato will help them with their pitch problems. In fact, music students are taught that, unless marked in music, vibrato is assumed and even mandatory. However, in the past, vibrato was used only as an ornament in certain passages of music. Some famous composers even rejected the use of vibrato, contrary to today's common practice.
Just touching the string with a finger and not pressing down can create harmonics. This means that instead of the normal solid tone a wispy-sounding note of a higher pitch is heard. This is caused by the light finger blocking the string's fundamental; the string must be touched exactly at a "node", an even division of the string, for example exactly half-way along the length of the string, or exactly one-third along the length of the string. When one touches the node at one of these points, the string vibrates in parts: either in halves or thirds, in these two examples. The pitch produced in these two cases will be an octave higher in the case of halves, and an octave and a fifth higher in the case of the string vibrating in thirds. This way, different members of the string's harmonic series are allowed to sound. If the pressure on the string is too deep, the harmonic will not sound, and a scratchy, unclear sound will resonate, so it is essential to touch the node lightly.
Harmonics are marked in music with a little circle above the note that determines the pitch of the harmonic. There are two types of harmonics: natural harmonics and artificial harmonics.
Natural harmonics are the type of harmonic described in the first paragraph of this section, and are achieved by simply touching the string with one finger at a node point. This is a relatively easy technique, and can be done by most beginner to intermediate students.
Artificial harmonics, however, are much more difficult. They requires pressing down a finger on one string (for example, first finger on the D string on the note "E"), and having another finger just touching the string a fourth higher, in this case on the position of the note "A". When the violinist stops the string with the first finger, and touches it lightly with the fourth finger in this way, the node one-fourth of the way along the string is touched, and the string will vibrate in four parts, sounding a tone two octaves above the note that is stopped (in this case, E). The distance between the two fingers must be extremely accurate, or else the harmonic will not sound. In addition, the pressure from the bow and the two fingers must be exactly right or it will not sound.
The "harmonic finger" can also touch at a major third above the pressed note, or a fifth higher. These harmonics are less commonly used because they are even more difficult to make sound well. In the case of the major third, the harmonic is higher in the overtone series, and does not speak as readily; in the case of the fifth, the stretch is greater than is comfortable for many violists. The sounding pitch of the major third harmonic is two octaves and a major third above the lower note, and in the case of the fifth, it is an octave and a fifth above the lower note.
Traditional notation of artificial harmonics uses two notes on one stem: the lower note employs a round note-head representing where the string is strongly stopped with the first finger, and the upper note uses an open diamond note-head representing where the string is lightly touched with the fourth finger.
The viola produces louder notes when the player either moves the bow faster or pushes down harder on the string. The two methods are not equivalent, because they produce different timbres; pressing down on the string tends to produce a harsher, more intense sound.
The location where the bow intersects the string also influences timbre. Playing close to the bridge (sul ponticello) gives a more intense sound than usual, emphasizing the higher harmonics; and playing with the bow over the end of the fingerboard (sul tasto) makes for a delicate, ethereal sound, emphasizing the fundamental frequency.
Occasionally the strings are struck with the back of the bow (col legno). This gives a much more percussive sound, and is most effective when employed by a full orchestral viola section, since it produces little volume.
A second, more modern percussive technique is called the "chop," in which the hair near the bottom of the bow is struck against the strings. It is used by some jazz musicians, including the Turtle Island String Quartet.
Violas are tuned by twisting the pegs in the scroll, around which the strings are wrapped. The A string is tuned first, typically to 440 Hz (see Pitch (music)). The other strings are then tuned to it in intervals of perfect fifths using double-stopping. Most violas also have adjustors (also called fine tuners). These permit the tension of the string to be adjusted by rotating a small knob. Such tuning is generally easier than using the pegs, and adjustors are usually recommended for younger players. Adjustors work best, and are most useful, with higher tension metal strings. It is very common to use one on the A-string even if the others are not equipped with them.
Small tuning adjustments can also be made by stretching a string with the hand.
The tuning C-G-D-A is used for the great majority of all viola music. However, other tunings are occasionally employed (for example, tuning the C string up to D), both in classical music (where the technique is known as scordatura) and in some folk styles.
The viola is almost completely limited to classical music, and even so is less often used for solo concerti and sonatas than the violin and the cello. This is often attributed to its sound, which, being mellower and less brilliant and flexible than that of the violin, is less suited to continuous solo use or virtuoso display.
Music for the viola differs from that for the violin and cello in its use of the alto clef, otherwise little used in the orchestra. Viola music also employs the treble and, very rarely, bass clefs.
In orchestral music the viola part is frequently limited to the filling in of harmonies with little melodic material assigned to it. A rare example of a piece written before the 20th century which features a solo viola part is Hector Berlioz's Harold In Italy, though there are also a few Baroque and Classical concerti, for example those by Telemann and Carl Stamitz.
The viola plays an important role in chamber music, though seldom a soloistic one. In the string quartet, the function of the viola is comparable to its function in the orchestra, usually filling in the inner harmonies. Mozart succeeded in liberating the viola somewhat when he wrote his six string quintets, which are widely considered to include some of his greatest works. The quintets use two violas, which frees the instrument (especially the first viola) for solo passages and increases the variety and richness of the ensemble. Johannes Brahms wrote two greatly admired sonatas for viola and piano, his Opus 120 (1894); these were, however, transcriptions of sonatas originally written for the clarinet.
In the 20th century, more composers began to write for the viola, encouraged by the emergence of specialised solo violists such as Lionel Tertis. William Walton and Béla Bartók have both written well-known viola concertos. One of the few composers to write a substantial amount of music for the viola was Paul Hindemith, who was a violist himself. Rebecca Clarke is a 20th century composer who wrote extensively for the viola. However, while the amount of music in the viola repertoire is quite large, the amount written by well-known composers is relatively small, and violists often resort to arrangements of works originally written for violin or other instruments.
The viola ("Bratsche" in German) is also an important accompaniment instrument in Hungarian and Romanian folk string band music, especially in Transylvania. Here the instrument usually has only three strings, tuned g - d' - a (note that the a is an octave lower than found on the classical instrument), the bridge is flattened and the instrument usually only plays triads in a strongly rhythmic manner.
Violas and violists are often the target of the musical equivalent of the blonde joke. This is probably the result of the mostly obsolete practice in nineteenth- and early twentieth-century orchestras of demoting to the viola section violinists who lose their playing ability as a result of age or lack of practice.
There are very few real viola virtuosi, likely owing to the shortage of music featuring the instrument. Among the better known violists, from earlier in the twentieth century are Lionel Tertis, Paul Hindemith, William Primrose, and Walter Trampler , and from more recently, Yuri Bashmet , Kim Kashkashian, Jerzy Kosmala , and Tabea Zimmermann .
The term violist is not universally used in English; some players, generally British, prefer viola player.
The viola in popular music
The viola also sees little use in popular music. It was sometimes part of popular dance orchestras in the period from about 1890 to 1930, and orchestrations of pop tunes from that era often had viola parts available. The viola largely disappeared from pop music at the start of the big band era. John Cale, a classically trained violist, played the instrument to great effect (amplified and often distorted) on two Velvet Underground albums, The Velvet Underground and Nico and White Light/White Heat.
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details