ORCHESTRA

Orchestra

String Instrument Anatomy

The basic principles of construction are the same for the violin, viola, cello and bass The differences are primarily in relative measurements. The proportions must be adjusted to produce the proper “mass of air” on which tone quality depends.

A LOOK INSIDE

Although ordinarily one does not see a violin with the top off so that interior construction details are visible, it is possible by looking through the F-holes to see the bass bar, the sound post, the linings and the corner blocks.

Such close interrelationships exist between the parts that each affects the other. Such factors as the grain of the wood, the graduation and arching of the plates, the size of the instrument, and even the climate may call for minute differences in dimensions. These slight variations may be observed in instruments by the same maker, whether by Stradivarius or others of the great early makers or by modern craftsmen.

CROSS SECTION

BRIDGE

The wooden bridge is the medium that conducts the vibrations of the strings directly to the violin's top and to the back by way of the sound post. The left foot of the bridge stands exactly over the bass bar, the right foot over and in front of the sound post.

		SOUND POST The sound post is a stick of fine, even-grained pine, about ¼” in diameter (for full size violin), just long enough to touch both top and back. It is not glued in but is so fitted as to hold its position. Its fibers form a right angle with the fibers of the top and the back. Its exact position depends entirely upon the quality and peculiarities of the instrument, thus requiring individual fitting. The sound post, with the bass bar, constitutes the interior “nervous system” of the instrument and the tone quality depends upon their proper construction and position.

SOUND POST

The sound post is a stick of fine, even-grained pine, about ¼” in diameter (for full size violin), just long enough to touch both top and back. It is not glued in but is so fitted as to hold its position. Its fibers form a right angle with the fibers of the top and the back. Its exact position depends entirely upon the quality and peculiarities of the instrument, thus requiring individual fitting.

The sound post, with the bass bar, constitutes the interior “nervous system” of the instrument and the tone quality depends upon their proper construction and position.

SIDES RIBS

Six (6) strips of maple about 3/64” thick, the grain running lengthwise, the figure across.

SCROLL and NECK

Usually carved from one block of maple, with the figure usually chosen to match the sides and the back. The carving of the scroll is one of the outstandingly individual characteristics of any instrument. Its function is to hold the pegs.

The function of the neck is to support the fingerboard and withstand the tension of the strings. The shape and size are important to the player. The neck must be fixed in position so that when you look at the instrument from the side, the eye of the scroll is approximately in a line with the edge of the back.

The angle at which the neck is set also determines the height of the fingerboard and its proper rise in proportion to the instrument.

SHOULDER

The part of the neck that fits into the upper block and is glued to the button.

INSIDE OF BACK

The back, also called a “plate”, is made of maple usually, with the grain running lengthwise and the figure across. It may be one or two-pieces. If of two pieces, they are out from the same block of wood, with the figure (flame, curl) matched at the center joining.

The graduation of the back varies from about 3/16” at the center to 5/64”-3/32” in the cheeks and, at the edge, 1/8”-5/32”.

BUTTON

The small rounded projection of the upper end of the back, to which the shoulder or heel of the neck is glued.

BLOCKS

6 pieces of wood, usually spruce or willow, of an even and not too wide grain, set perpendicularly to the top and the back. They strengthen the whole body of the instrument. In some inferior fiddles, the corner blocks and side linings are omitted.

Upper or Neck Block
into which the neck is fitted. It is about 21/8” by 17/32” or 9/16”. To it are attached the belly, back and ribs.
Corner Blocks
Hold the ribs together at the corners and provide a means of anchoring the mid-rib linings solidly.
Bottom Block
The belly, back and the ribs of the lower bout are attached to it. About 21/8” by ½”, it holds the endpin, and reinforces the body of the instrument.

END BUTTON

The small round pin of ebony, with a rounded head, over which the tailpiece gut is hooked. For cello and bass, this term also includes the extension, usually of metal, which supports the instrument in playing position.