Viola.

The viola is bowed instrument similar to the violin but two to three inches longer and a fifth lower in range. It is the alto voice family. The viola was not used by composers as a separate, distinctive part of a musical piece until the 18th century, when Haydn, Gluck, and Mozart began to incorporate it into their work.

Viol.

The viol, a precursor of the violin and cello, is a member of the group of instruments known as chordophones. It has six strings and is fretted like a guitar but played with a bow like a violin or cello. This instrument is a bass viol made in Britain in 1713. The viol was very popular between 1500 and the mid-1700s. It is used today mostly to play early music and, occasionally, chamber music.

Violin.

This violin is perhaps the best-known Western orchestral instrument. Its distinctive tone is due in part to a sound post and a bass bar, both of which are located inside the instrument and used to transmit and distribute vibration. Two other characteristics of the violin are the fretless fingerboard made of ebony and the four string tuned in fifths.

Black Sea Fiddle.

This Black Sea Fiddle, a folk instrument from Georgia, Central Europe, (circa 1865), is made of wood with inlaid ivory. It is similar to the Caucasian fandur, with its bottle-shaped body. The Black Sea Fiddle is a member of the family of musical instruments known as chordophones.

Cello.

The cello (also known as the violoncello) is bass voice in violin family. It is held between the knees of the musician and has a retractable pin at the bottom that can be clamped in different positions to change the height of the cello from the floor. This instrument has a bow shorter and thicker than that of a violin.