The viola is the alto voice in the string family. Like the violin, it is held under the chin, resting on the shoulder. Unlike the violin, the viola is slightly larger and is tuned a perfect fifth lower. It has a darker and warmer tone quality than the violin, but is not as brilliant. The viola has 4 strings, in order from lowest to highest: C3, G3, D4, A4 and music for the viola is written in Alto clef, with the Treble clef used for high passages. Traditionally, the viola has served as one of the inner voices and has the ability to be either a harmonic or melodic voice in textures. Much of the Orchestral repertoire is filled with good examples of the viola in harmonic/rhythmic roles. From the start of the 20th century onwards, the viola started to be used in more diverse roles.
Timbre and range
<music> \meterOff \cadenzaOn \clef alto <c, g' d' a'>1 c \glissando \clef treble e \harmonicOn \octaveOn e' \harmonicOff </music>
The viola is not proportional in size to the violin. In order for the viola to be the correct size for the appropriate acoustical phenomena to occur, the instrument would have to be larger in depth than is practical to hold under the player's chin (although a type of early viola, known as a tenore, was built according to these proportions). Violas are built according to the length of the back and players choose an instrument according to the size of their left hand, between 15 and 17 inches for adults. The instrument does not project as well as the violin. However, due to its lower pitch and larger body compared to the violin, the viola has a dark, almost reedy tone that can vary from instrument to instrument. The lower range of the viola is limited by its lowest string. Without scordatura techniques, the lowest possible note on the viola is C3, while the upper range can vary from player to player. The viola has a range of some 3+ octaves from the low C string all the way up to the high E on the A string. The upper range can be further extended through the use of artificial harmonics, a demanding technique usually only reserved for solo repertoire.
Use of treble clef
Although the viola part is traditionally written in the alto clef, extended passages in the upper register may be written in the treble clef as is done with the violin. The composer is reminded that not all amateur violists will be fluent in reading the treble clef. At the professional and collegiate levels, most violists will be fairly able to perform music written in the treble clef, and this should be of no great concern to the composer. It is at the high school and community orchestra level that the composer must be wary. High school ensemble viola music should not extend far into the upper register (the treble clef, therefore, should be used uncommonly or not at all), and community orchestra violists should not be expected to use the treble clef, despite the technical capabilities of the players. Unlike the violoncello, whose players are used to rapidly changing between clefs, violists prefer to switch to the treble clef only if there is an extended passage which lies above a reasonable number of ledger-lines in alto clef.
The basic techniques of string playing common to all members of the bowed string family are covered in the articles Bowing Technique and Scoring for strings. It goes without saying that unless you are writing for professional musicians, the parts must be tailored to the ensemble's technical ability. A few points pertinent to the viola are discussed here:
- The viola, in the hands of a capable player, is capable of practically the same level of virtuosity as the violin or the violoncello. However, the larger size of the instrument presents certain practical difficulties which no amount of technical prowess can avoid. In particular, it is much more difficult to place the left hand in high positions especially on the lower three strings owing to the thickness of the body and distance from the player's chin. Therefore writing above fourth position on the C, G and D strings should be done with caution.
- As with the violin, perfect fifths are difficult to tune due to the angle the left hand must be at. Also be careful how far you ask a violist to stretch for a chord in the neck positions, as the player will not be capable of reaching as far as on the violin.
- The increased size and weight of the instrument when compared to the violin also present another problem: fatigue. The viola is unfortunately not designed with ergonomic considerations in mind, and holding the instrument for long periods of time can cause long-term muscular and nervous problems, particularly in the spine, shoulder and left hand. It is therefore recommended that, particularly in solo writing, the player have some opportunity to rest the instrument for short periods of time, as is indeed good advice for any instrument.
The viola and violin family developed sometime around 1500 in Italy from previous bowed instruments. Among the most popular of the earlier string instruments was the Viol da Gamba. The shape of the viola and violin as it is today was not invented but was rather the result of an evolution of various forms, by different craftsmen. History remains allusive as to which of the modern string instruments was the first created. It is most likely that all the different sizes of instruments were developed at the same time from older bowed instruments till the makers found what they considered the ideal model.
As with Violin, certain instrument makers are preferred over others.
Andrea Amati - was one of the first luthiers to make violas, small and large ones. Amati was so famous in his time, King Charles IX of France commissioned him 38 instruments (violins, violas and cellos) for his musicians. Most of those masterpieces were destroyed during the French revolution but one viola survived and you can see it at the Ashmolean Museum in Oxford.
Gasparo da Salò
Andrea Guarneri - was the first of another celebrated family of luthiers, with his two sons and grandsons. Because of the reduced demand, the Guarneri family built very few viola, most of them by Andrea who made mainly small violas. William Primrose also owned and played one of these, which is one of the most famous violas.
Antonio Stradivari - made few violas and even experts are not sure about the numbers, something between ten and eighteen. In 1690 he built a quintet of instruments for the Medici family court in Florence, including two violas: a small one, contralto (40.64 cm/16”), and a large one, tenor, with a body length of nearly 48 cm (over 18”). One of these few instruments was played by Niccolo Paganini and inspired him to commission a concert piece, Harold in Italy.
- C.P.E. Bach
- Wolfgang Amadeus Mozart
- Ludwig van Beethoven
- Felix Mendelssohn
- Niccolo Paganini
- Paul Hindemith
- Ralph Vaughn Williams
- William Primrose
- Lionel Tertis
- Rebecca Clarke
- Yuri Bashmet
- Kim Kashkashian
- Leonard Slatkin
- Lawrence Power
- Maxim Vengarov
The Viola Website 
Viola Wikipedia 
Viola in Music 
|Instruments and Voices|
|Woodwinds||Flute (Piccolo/Alto/Bass) • Recorder • Oboe (Cor Anglais/Oboe D'amore/Heckelphone) • Clarinet (E♭/Bass/Contrabass) •|
|Brass||Horn • Cornet • Trumpet • Trombone • Euphonium • Tuba • Saxhorns|
|Keyboards||Piano • Organ • Harmonium • Harpsichord • Clavichord • Celesta • Accordion|
|Percussion||Tuned: Timpani • Glockenspiel • Chimes • Vibraphone • Xylophone • Marimba • Crotales • Musical saw • Hammered Dulcimer|
|Electronic||Theremin • Ondes Martenot • Synthesizer • Electronic Wind Instrument|
|Stringed||Bowed: Violin • Viola • Violoncello • Contrabass|
|Voices||Female: Soprano • Mezzo-soprano (often mistaken with Alto) • Contralto (often mistaken with Alto)|