The four major instruments in the string family, the violin, the viola, the cello and the double bass, are built the same way. The instruments are made of many pieces of wood which are glued - never nailed - together. The body of the instrument is hollow, thus becoming a resonating box for the sound. Four strings (sometimes five on the double bass) made of animal gut, silk, nylon, palm fiber or steel are wrapped around pegs at one end of the instrument and attached to a tailpiece at the other. They are stretched tightly across a bridge to produce their assigned pitches.
The double bass, or string bass, is the largest and lowest instrument of the string family. The double bass has sloping shoulders, instead of rounded shoulders like the other string instruments. This allows the player to have more room to move his or her arms, hands, and fingers in front of the instrument. Because of its size, the player stands or sits on a high stool to play the double bass.