Violin typically are lower in pitch than the G-string; these strings are usually tuned to C, F, and B. If the instrument's playing length, or string length from nut to bridge, is equal to that of an ordinary full-scale violin; i.e., a bit less than , then it may be properly termed a violin. Some such instruments are somewhat longer and should be regarded as violas. Violins with five strings or more are typically used in jazz or folk music. Some custom-made instruments have extra strings which are not bowed, but which sound sympathetically, due to the vibrations of the bowed
Violin family have four strings each, are tuned in fifths (except the double bass, which is tuned in fourths), are not fretted and have four rounded bouts while always having a sound post and bass bar inside. In contrast, the viol family instruments usually have five to six strings with a fretted fingerboard, are tuned in fourths and thirds, often have sloping shoulders, and do not necessarily have a sound post or bass bar. The instruments of the violin family are the most used bowed string instruments in the world today. Although all share a place in classical music, they are also