Types of Violas
The viola has been the subject of constant change over the entire extent of its lifespan, due to its imperfect form relative to that of the violin. A wide variety of different types of viola have been produced - which does lead to problems when categorising and explaining the different types of viola. However, viola types can be roughly categorized into three groups: violas that vary in size, violas that vary because of time period and the less common violas that vary due to musical purpose or genre. These variations of the viola can have some quite significant changes, especially to the length and width of the instrument.
It is important to note that while these are the three main categories for types of viola, in general violas are very individualistic instruments. Variations in makers, country of origin, wood-types and make (for example, whether the viola has a one-piece or a two-piece back) also have a significant effect on the quality of the viola and subsequently the tone produced by the instrument.
Different Types of Viola by Size
The viola has had a comparatively large development period, with few rigid guidelines in place regarding the size and specifications of the instrument. This is because the lower range of the viola requires a larger sound box to create a full tone. The size of the sound box needed to create this full-bodied tone would make the instrument too big to hold under the chin. Consequently, the viola has undergone a lot of changes: including various changes to the size and shape of the soundbox, as well as to the length of the fingerboard as craftsmen have tried to develop the sound, timbre and range of the viola. These evolutions have mainly aimed to make the viola as similar to the violin in sound and style as possible, which may account for why the viola is still played under the chin. Full-size violas can vary in length from around 14-15 inches to over 17 inches.
Alto and Tenor Violas
Violas were initially designed in two sizes: alto and tenor. The tenor viola was designed to play a lower part than the alto viola, and so had a bigger body in order to achieve a more pleasing tone in the lower register of the instrument. The alto was meant to cover the higher-middle range, and so did not quite need to be the same size as the tenor viola. Together, these violas were used to cover the mid-range notes in four and five-piece string ensembles, with as many as three violas initially being used in a five-part arrangement. However, as the violin grew in popularity and instrument makers made more violins, they neglected the viola, which also began to be used less often in string arrangements. Today, there are still significant differences in the sizes of violas produced.
Violas for Children
Violas tend not to have children's sizes, however child-size violins can be strung with viola strings so that children may learn to play the viola. Child-sized violins are called 'fractional' violins as their size is recorded as fractions of a whole or 'four-quarter' violin. Fractional violins can come as small as 1/64, although this is very rarely used. The smallest commonly played violin is the 1/16th, which is used by children aged 3-5, depending on the length of the child's arm. Violin sizes above 1/16th include the 1/10th, 1/8th, 1/4 or 'quarter-size', the 1/2 or 'half-size' and the 3/4 or 'three-quarter' size.
Different Types of Viola by Time Period
Pre-Baroque Stringed Instruments
Before the viola was invented, a number of other stringed instruments similar to the viola were used. The term viola itself was used well before the invention of the Baroque viola as a name for an instrument held under the chin and bowed. Instruments that pre-date the Baroque viola include the lira of the Byzantine Empire that was held upright, and the lira de braccio (viol for the arm) that was held against the chin like a viola. The three-stringed violetta, which also pre-dates the viola, was also held under the chin. The viol family again was similar in construction to the violin family, and also became popular at around the same time. Sometimes these instruments are referred to as types of early violin family instruments - and especially as 'violas' as some were known by this specific name. However, all of these instruments are separate instruments in their own right, and should only be seen as grandparents of the viola in order to differentiate them from the type of viola that we are familiar with today.
The forefather of the classical/modern viola, this viola was the first instrument made in the 16th century. The Baroque viola has a shallower angle of the neck, which is also usually thicker to support the tension of the strings, although the string tension is lower than on a classical viola. There were two main types of viola at this stage - the alto and the tenor (see 'Different Violas By Size' section for an explanation). As more advanced crafting techniques allowed for the range of the viola to be extended in the 18th century, many of these original Baroque instruments were altered in order to fulfil these new standards.
Classical Viola (Also referred to as the Modern viola or the Acoustic viola)
The classical viola was developed in the late 18th and early 19th century as new techniques became available to increase the string tension and therefore the range and sound projection of the viola. Even at this stage however, there were still significant variations in the size of the viola (unlike the violin, which maintained a standard size from the Baroque model). The classical viola has a more slender neck, higher string tension, and is the type of viola that we are most familiar with today. More recently, classical violas have been made from many different woods, and more comfortable fittings have been developed to aid the violist - like the chin rest, which can stop the player from dropping the viola when changing from one position to the next and helps the player to hold the viola against the neck comfortably. Better strings and rosins have also been invented in the 20th century which has improved the sound quality produced by the classical viola.
The electric viola is a viola that produces sound electronically. There are many different styles of electric viola, and as no sound box or f-holes are needed in order to produce sound, so many forego the traditional aesthetics of the classical acoustic instruments. Electric violas were sold as early as the 1930's, with musicians being known to use pick-ups on violas before this date also. The sound from electric violas can be distorted through the process of amplification, which is helpful in some genre playing. Electric violas are rarer than electric violins, mainly because of the viola is less popular and therefore less units will ultimately be sold.
Semi-Electric (Also known as Electric-Acoustic or Violin with Pick-Up)
A semi-electric viola is essentially a viola that produces sound acoustically which is also fitted with a pick-up so that the sound can be electronically amplified. This kind of sound retains more of the original acoustic feel than fully electric violas, which will not sound particularly loudly when not plugged in to an amp (much like electric and bass guitars). Pick-Ups are relatively easy to add to classical violas; however some set-ups require the modification of the viola (for example, a hole being made in the body of the violin so a 'plug-in' can be inserted).
Different Types of Viola by Genre
The 5 string can be either electric or acoustic, and as its name suggests it includes a 5th string - the E string (above the A string.) The 5-string viola combines the ranges of the violin and viola in the one instrument. The five-string viola can take some time to adapt to for four-string viola players as the angle that the bow touches a specific string changes. This type of viola adapts well to country fiddle music as it allows for the player to have an extended range, and the decreased angle between strings makes it easier to perform double and triple-stops (playing two to three strings at a time).