Learning to choose the best viola strings requires understanding the differences between the three main types of viola, violin and cello strings. There is definitive use of the term “best” when relating to musical instruments, because different people want different things from their strings. Gut core strings provide the most complex overtones but are more prone to going out of tune. Steel core strings give a bright tone, are very durable in terms of tuning and have a clear sound. Synthetic core strings have the complex overtones found in gut string with much more reliability with regard to tuning.
Viola strings are comprised of a core material with another material wound around it. The difference in materials used in the core material affects the tone produced by the strings most profoundly, and the gauge of the strings can affect the volume and tone. A string’s gauge is simply its thickness or heaviness, and viola strings usually are referred to as light, medium or heavy. Generally, medium-gauge synthetic strings are the most popular, but steel core strings are better for beginners and people who are not interested in playing classical music.
Original viola strings were gut strings made entirely using sheep’s guts. In modern times, the gut is used only as a core and is wrapped in silver or copper, preserving the tone of the gut string. Gut strings are preferred by baroque musicians and have a rich sound brimming with overtones. The depth of tonality of these strings is what attracts many players to them, but they are sensitive to changes in temperature and humidity.
Steel core strings generally are used by beginners or players who do not play classical music. The tone provided by steel core strings is brighter, with accentuated high-end tones and very few overtones. The main benefit of steel core viola strings is durability, and they will stay in tune and keep their tone for much longer than gut strings.
The final type of viola strings are synthetic core strings. These have a nylon core and basically combine the most favorable elements of the other two varieties of string. They have the complex overtones and rich low end of gut strings combined with the durability of steel core strings. If the player is primarily interested in the richness of tone or excessive durability, steel or gut strings might be the better choice, but for most players, synthetic core strings are the best option.
Gauges of viola strings also have an effect on the playability, volume and tone of the strings. Thinner strings are easier to fret, which can be an issue for beginners, but they provide less volume and a brighter high end. Thicker strings therefore give the player increased volume and low end power but might be more difficult to fret for beginners. Generally, medium gauge strings will be suitable for most players.