Construction and Design of a guitar

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Once you understand the basics about how an acoustic guitar is designed and built, you will be able to see and hear subtle differences that will help you choose the best guitar for your needs.

Neck
The neck of an acoustic guitar is joined to the guitar body and terminates at the headstock. The fretboard is mounted to the neck's top, and the back is shaped to accommodate the player's fretting hand.

Most acoustic guitars use a set neck, which means the neck is glued onto the body of the guitar. The alternative is a bolt-on neck, more commonly used with electric guitars. A heel provides additional support at the back of the neck, where it meets the body of the guitar.

The neck contains a metal truss rod that prevents it from bowing and twisting due to string tension and environmental factors. Adjusting the truss rod can correct intonation issues that prevent the instrument from being tuned properly. This truss rod can be adjusted either at the headstock, or just inside the body of the guitar, at the base of the neck.

The fretboard, or fingerboard, on the top side of the neck, is usually a separate piece of wood that is glued to the neck. Fretboards are typically constructed out of rosewood or ebony.

Thin strips of metal, called frets, are embedded in the wood at half-step increments along the 12-tone scale, to indicate where different notes are played. Most guitar fretboards have inlaid dots or symbols on the odd-numbered frets, starting with the third - excluding the 11th and 13th in favor of the 12th, or the octave.

The headstock is located on the end of the neck opposite the guitar body. It is fitted with tuning keys, also known as tuners, tuning pegs, or machine heads. These adjust the tension of each string, changing their pitches. The nut is a small strip located where the headstock meets the neck, that is grooved to guide the strings onto the fretboard. On an acoustic guitar, the nut is commonly made of plastic, but it can also be bone, graphite, or any number of other materials.

Body

The body of an acoustic guitar is composed of the top, also called the soundboard. The soundboard is supported by internal bracing; the sides, and the back that together form a hollow chamber. The upper body curves are referred to as the upper bout, while the usually larger lower body curves are called the lower bout. The area between them is referred to as the waist.

The size and shape of the body influences both the sound and playability of the instrument. Finding a body shape that matches your physical and musical needs will help ensure you choose the right acoustic guitar. See Body Styles - Comfort and Resonance below for more.

The sound hole, through which sound projects, is aligned with the waist, at the base of the fretboard and is often fitted with a protective pickguard made of plastic or other materials.

The guitar's strings are mounted to the body of the guitar at the bridge. Bridge pins anchor each string. The thin strip of either bone or plastic that spaces out the strings on the bridge, is called a saddle. The bridge transmits string vibrations to the guitar's top resulting in the instrument's sound output, also referred to as projection.