The distinctive hourglass shape of a violin is instantly recognizable, though not many people would know that the elements of that shape are called ’bouts.’ The concave center of the hourglass curve is called a C-bout, while the convex section toward the neck is called the upper bout and the convex curve near the tail is called the lower bout.
A violin has four strings stretched from the bottom of the body across the front up the neck to the scroll. The fitting for the strings at the bottom of the body is called the tailpiece. The flattish top of the violin over which the strings stretch is called the soundboard, table, belly or table and is usually made of spruce. The back and sides of the violin and the ribs inside are usually made of maple. Two endblocks inside at either end of the body provide the bracing for the neck and the tailpiece. Completing the fittings of a violin are the internal soundpost and bass bar and the external bridge, the combination of which transmits the vibration of the strings to the entire body of the violin. A violin may also include a chinrest that is attached on or near the tailpiece.
The edge of a violin soundboard typically has a bead of wood called a purfling. The purfling protects the body from cracks that might originate on an unprotected edge and also allows the soundboard to flex more easily.
The neck of the violin is usually made of maple and holds the fingerboard, the area of the violin where the violinist presses the fingers of their left hand against the strings. The fingerboard is usually made of ebony, though it is sometimes made of dark-stained wood. Fingerboards curve across their width and also have a small concavity or scoop that increases toward the side for the lower strings.
The bridge, bass bar and soundpost, just above the tailpiece, form the sounding apparatus for the violin. The bridge is carved precisely to be an anchor point for all the strings, as well as holding the strings at a precise height above the fingerboard all the way up the neck. The soundpost fits unglued inside the body tightly under the bridge’s treble foot between the soundboard and the back of the violin; the bass bar fits under the other end of the bridge.
The tailpiece of the violin forms an anchor for the strings — the scroll at the top of the neck forms the other anchor. The tailgut of the tailpiece fastens all the strings tightly by looping them around the tailpin. Tuning levers and fine tuners are sometimes attached to each of the strings within the tailpiece.
At the other end of the violin, the scroll contains tuning pegs fitted within a pegbox. Each string is attached to one tuning peg; turning the peg loosens or tightens the string. Strings are made of stretched animal gut that, though called catgut, usually come from sheep. Other modern materials used for strings include nylon, stranded steel and steel plated with either silver or gold. Strings have a silk wrapping of various colours at either end to make it easier to attach the string to a tuning peg and to the tailgut.
The bow, up to 75 cm (29″) long and weighing about 60 g (2 ounces) is simply a long stick with a horsehair strand strung between the tip and the heel, also called the frog or the nut. There is a screw adjuster at the heel to loosen or tighten the strand. The grip for the bow is made of wound leather and forms a cushion for the violinist’s right hand.